Description
The Resolver In functionality of the OPAL-RT Board driver provides the simulation the possibility of receiving resolver signals through the analog input channels of the OP5340 modules installed in the simulator.
In the case of the OP4200 chassis, the OP5340 module is incorporated into the I/O cassette with ID OP4240-1.
The functionality is based on the basic two-pole resolver. There are two resolvers implemented in each subgroup of 8 analog in channels.
The Resolver In has two operation modes: the standard one, where configuration parameters are applied before the simulation's start and the calibration mode, where the parameters are updated through connection points at run-time.
The values always provided back to the simulation through connection points for each resolver are the Speed and Angle retrieved from the resolved signals.
If the resolver is in calibration mode, the following connection points are also made available:
| Damping Factor (Ksi) | value from model to interface |
| Natural Frequency (w0) in Hz | value from model to interface |
| Use Internal Carrier for Demodulation | value from model to interface |
| Internal Carrier Delay in s | value from model to interface |
| Internal Carrier Frequency in Hz | value from model to interface |
| Generated Carrier Amplitude in V | value from model to interface |
| Generated Carrier Offset in V | value from model to interface |
| Expected External Carrier Amplitude in V | value from model to interface |
| Expected External Carrier Offset in V | value from model to interface |
| Sine Amplitude in V | value from model to interface |
| Sine Offset in V | value from model to interface |
| Cosine Amplitude in V | value from model to interface |
| Cosine Offset in V | value from model to interface |
| Scaled Carrier Wave, | value from interface to model |
| Scaled Sine Wave | value from interface to model |
| Scaled Cosine Wave | value from interface to model |
The connection points above (apart from the last 3) are used to tune the parameters required by the Resolver In functionality during execution. When the resolver is not in calibration mode (i.e. it is in standard operation mode), then the parameters are configurable through the interface's UI and are sent to the FPGA once, at the beginning of the simulation. For a detailed description of what each parameter does, please check the Usage section below.
The last 3 connection points are inputs to the model and they represent the waves that were used to resolve the received signals (the carrier, sine and cosine waves).
Usage
Once the bitstream configuration file has been parsed, the location of the analog input modules becomes visible to the user. The channels of the modules are grouped into bunches of 8. By clicking on each group of 8, the user has access to the configurable options of the group.
Channel group configuration
| Name | The name of the channel group denotes the physical channels of the analog input module the current configuration will be applied to. |
| Enable | Checking this box will enable the acquisition of resolver data for the channels in the group once the simulation has started, provided that the type of functionality is set to Resolver In (see item below for more detail). Clicking on Enable also makes each resolver's (2 resolvers per subgroup) angle and speed available as connections in HYPERSIM. This means that if the user wishes to monitor these values, connections must be made between points in the model and the resolver input connectable points. If the Calibration mode check-box for the current resolver is checked, then the connection points mentioned in the Description section will also be made available. Scaled Carrier Wave, Scaled Sine Wave and Scaled Cosine Wave represent model inputs. The other calibration parameters represent model outputs. |
| Type | This grayed-out field has the purpose of displaying to the user the functionality of the current channel subgroup. For the receiving of resolver data, please verify that the field displays Resolver In. |
The two resolvers present in the current channel group are split into two sections: ResolverIn 1 and ResolverIn 2. The parameters described below are the same for both resolvers. Their description also applies to the additional connection points created when the Calibration mode box is checked.
| Calibration mode | By checking this box, the calibration mode is enabled for the current resolver. Therefore, the user can decide if the resolver's parameters are to be tuned during the simulation or if they are to be applied during the initialization phase of the model. When this box is checked, all other of the current resolver's parameters are removed from the interface's configuration and are made available as connection points. It should be pointed out that this mode (when enabled) is relying on a slower communication link between the FPGA and the CPU (use of LoadIN blocks) and thus is not meant for high-performance simulations (given that the exchange of CPU-FPGA data is done at every computation step). It is, as its name suggests, meant to be used to calibrate the resolver to work well with the equipment it is connected to. The calibrated parameters should then be applied in the interface's UI in order to be transmitted to the FPGA once, during the initialization phase of the model for all subsequent simulation executions. |
| Damping factor (Ksi) | This parameter specifies the filter's damping factor. |
| Natural frequency (w0) in Hz | This parameter specifies the filter's natural frequency. Is it expressed in Hertz. |
| Use internal carrier for demodulation | When this box is checked, the resolver will generate its own carrier for demodulation instead of using the one provided by an external device. This will also cause the Expected external carrier amplitude in V and Expected external carrier offset in V parameters to be replaced by Internal carrier delay in seconds, Internal carrier frequency in Hz, Generated carrier amplitude in V and Generated carrier offset in V. All these parameters are described below. |
| Expected external carrier amplitude in V | The expected amplitude of the carrier wave that is received during the simulation. The value should be between 0 and 16 V. A resolution of up to 0.001 V (1 mV) is permitted. This option is only visible if the Use internal carrier for demodulation box is unchecked. |
| Expected external carrier offset in V | The expected offset of the carrier wave that is received during the simulation. The value should be between -16 V and 16 V. A resolution of up to 0.001 V (1 mV) is permitted. This option is only visible if the Use internal carrier for demodulation box is unchecked. |
| Internal carrier delay in seconds | This parameter is the delay for applying the internal carrier with the resolved signals (sine and cosine). The value's range is 0 to 20e-6 (20 us). This option is only visible if the Use internal carrier for demodulation box is checked. |
| Internal carrier frequency in Hz | This parameter specifies the frequency of the internally generated carrier wave. The value should be between 0.01 and 90000 Hertz. This option is only visible if the Use internal carrier for demodulation box is checked. |
| Generated carrier amplitude in V | The internally generated carrier wave can be outputted through the channel of an analog out module. This parameter specifies the amplitude of the outputted carrier wave. The value should be between 0 and 16 V. The resolution of the value is up to 0.001 V (1 mV). This option is only visible if the Use internal carrier for demodulation box is checked. Note that there is no carrier wave outputted when the Use internal carrier for demodulation box is unchecked. |
| Generated carrier offset in V | The internally generated carrier wave can be outputted through the channel of an analog out module. This parameter specifies the offset of the outputted carrier wave. The value should be between -16 V and 16 V. The resolution of the value is up to 0.001 V (1 mV). This option is only visible if the Use internal carrier for demodulation box is checked. Note that there is no carrier wave outputted when the Use internal carrier for demodulation box is unchecked. |
| Sine amplitude in V | This parameter specifies the amplitude of the resolved sine signal. Its value should be between 0 and 16 V, with a resolution of up to 0.001 V (1 mV). |
| Sine offset in V | This parameter specifies the offset of the resolved sine signal. Its value should be between -16 V and 16 V, with a resolution of up to 0.001 V (1 mV). |
| Cosine amplitude in V | This parameter specifies the amplitude of the resolved cosine signal. Its value should be between 0 and 16 V, with a resolution of up to 0.001 V (1 mV). |
| Cosine offset in V | This parameter specifies the offset of the resolved cosine signal. Its value should be between -16 V and 16 V, with a resolution of up to 0.001 V (1 mV). |
Signals configuration
Channels in resolver input groups do not have any parameters to configure.
The table below shows how the resolver inputs translate to the physical channels of the analog input module.
| Index in group | Usage |
|---|---|
| 1st channel of the group | carrier wave input for the first resolver of the subgroup; this wave is used when the Use internal carrier for demodulation box is un-checked |
| 2nd channel of the group | received sine wave for the first resolver of the subgroup |
| 3rd channel of the group | received cosine wave for the first resolver of the subgroup |
| 4th channel of the group | not used by the Resolver In functionality; in loopback bitstreams, this input is generally used by the Resolver Out functionality to input an externally generated carrier wave |
| 5th channel of the group | carrier wave input for the second resolver of the subgroup; this wave is used when the Use internal carrier for demodulation box is un-checked. |
| 6th channel of the group | received sine wave for the second resolver of the subgroup |
| 7th channel of the group | received cosine wave for the second resolver of the subgroup |
| 8th channel of the group | not used by the Resolver In functionality; in loopback bitstreams, this input is generally used by the Resolver Out functionality to input an externally generated carrier wave |
The channel setup described above is the most common. There can, however, be changes to it, depending on how the bitstream was designed (i.e. using different analog input channels than the ones detailed above). In that case, special attention should be paid to how the external equipment is connected to the analog input module(s) of the simulator, so that the carrier, sine and cosine waves are processed appropriately by the Resolver In functionality.
In most bitstreams containing resolvers provided by Opal-RT, both the input and the output functionalities are present. Therefore, in most cases, the generated carrier wave for the first Resolver In of a subgroup is the fourth analog output channel (channel 3 or 11, depending on the subgroup); for the second Resolver In, it is the eighth analog output channel (channel 7 or 15, depending on the subgroup).
If there are any doubts about how the signals are routed, please consult the RT-XSG model used to generate the programmable bitstream file. If the model is not available, please contact Opal-RT support.
Characteristics and Limitations
For the connector pin assignments, the user should refer to the carrier documentation.
The current version of the resolver analog input functionality of the OPAL-RT Board driver has the following limitations:
- The detectable speed is in the range of -5300 Hz to 5300 Hz