Description

Block function

This block allows the configuration and the control of a Induction Machine model. The IM solver core is located on an FPGA-based board and runs at higher sample rate that the RT-LAB system.

Model equation

Park tranform

The model interfaces with phase-domain quantity but uses a d-q domain equation. The park transform used by the model is:

The model is computed using a fixed reference frame. The park transform above will be used with Theta = 0 for Stator quantities, and theta = -theta_rotor for rotor quantities.

Electrical equation

The machine model on FPGA is computing the following equation on the FPGA. Note that the electrical parameters of the model can be tuned using the parameters' entries of this mask.

Torque equation

The torque is computed on the CPU part of the simulator (unlike the electrical modeling portion). Here is the equation implemented for the torque calculation:

Mask Parameters

Motor Parameters Tab

Model mode: The drop down list of the model mode gives the option to set the machine parameters manually or by importing from JMAG-RT .rtt file. Accordingly, the corresponding fields in the mask are disabled.

RTT file name: The .rtt file name can be provided in single quotation mark to import machine parameters including stator/rotor leakage inductances (Lls/Llr), stator/rotor resistances (Rs/Rr), mutual inductance (Lm), and number of pole pairs. In this case, the machine parameters of the mask are disabled with the values extracted from the .rtt file. This motor support JMAG 10.5 or later version of .rtt files.

Parameters as inports of the block: When this parameter is checked, Input ports will be added to the block to allow to control the inductances and resistances parameters of the model from outside of the block. Note that changing the parameters will increase the CPU usage and fine tuning them in real time could generate overruns. Tip: increase the time step if the parameters are frequently modified to avoid overruns. Also note that these parameters can be change during real time simulation from the project tab of RT-Lab interface, by changing the values of "Rs" "Lls" "Rr" "Llr" and "Lm" constants that can be found in the signal tree.

Stator leakage inductance Lls: [H] Stator leakage inductance parameter in Henry of the induction machine model (also known as Lls).

Stator resistance Rs: [Ohm] Stator resistance parameter in Ohm of the induction machine model (also known as Rs).

Rotor leakage inductance Llr' (referred to the stator): [H] Rotor leakage inductance parameter in Henry of the induction machine model (also known as Llr'). This parameter must be set as referred to the stator.

Rotor resistance Rr' (referred to the stator): [Ohm] Rotor leakage resistance parameter in Ohm of the induction machine model (also known as Rr'). This parameter must be set as referred to the stator.

Mutual inductance Lm: [H] Magnetizing inductance parameter in Henry of the induction machine model (also known as Lm).

Pole Pairs: Number of the machine pole pair. It must be an integer from 0 to 63.

Fix referential angle: Since the model is computed in a fixed reference frame, this angle can be used to choose the reference angle. Default = 0.

Show Rotor/Stator Voltages override port: This checkbox allows the user to add input ports to the block, to be able to force the stator/rotor voltages. By default, the rotor voltages are forced to 0v (squirrel cage Induction Machine). By default, the stator terminal are connected to an inverter.

Solver Time Step: [sec] Value of the FPGA model time step. Minimum= 375e-9. Maximum= 2.5e-6.

Configuration tab

Hardware Controller Name (OpCtrl) Links this block to an OpCtrl block by entering the same 'Controller Name' as specified in the OpCtrl block. The OpCtrl block controls initialization of the settings of one specific FPGA-based card in the system.

FPGA Clock period: [sec] For information only: period of the FPGA clock.

Communication Port Numbers: Number of the communication port used to communicate with the FPGA core. Please check the bitstream documentation to setup accordingly this tab.

Inputs

rpm: Machine's mechanical speed in RPM.

Rs/Rr/Lls/Llr/Lm: Machine's electrical parameters when they are set as a block inputs. Note: these inputs are not value restricted, the parameters needs to be consistent to avoid instabilities.

force_v_stator|rotor: Boolean input to force the stator|rotor voltages to the vabc_stator|rotor_forced inputs provided to the block. These inputs are activated only if the checkbox "Show Rotor/Stator Voltages override port" is checked.

vabc_stator|rotor_forced: Voltage value that Vabc of the stator|rotor must be forced at. These inputs are activated only if the checkbox "Show Rotor/Stator Voltages override port" is checked.

rst: This input is a software reset. When set to "1", the solver is in the reset mode (reset of internal states and outputs to 0). When set to "0", the solver is not in the reset mode.

Outputs

IM_out: This output is a bus composed of machine's monitoring outputs.

Signal List:

• Iabc_stator
• Iabc_rotor
• Idq_stator
• Idq_rotor
• Phi_dq_stator
• Phi_dq_rotor
• Vdq_stator
• Vdq_rotor
• Theta_elec|mec
• Te
• ElecParams
• Speed_mec_rpm
• we

comm_status: Status of the communication ports. Composed of 3 elements: [DataOut DataIn(speed) LoadIn].

Running: This output gives the solver state. When 0, the solver is initializing. When 1, the solver is initialized and running.

Characteristics and limitations

Solving method: An induction machine model with fixed d-q (Park) referential was used.

Offline simulation: This block is not capable of offline simulation. Use the Simscape Electrical Specialized Power Systems (SPS) induction machine block for offline simulation.

Communication delays: The block latency is 2 CPU Time steps.

If you require more information, please contact https://www.opal-rt.com/contact-technical-support/.