This page includes the following components: | Resolver | | Name | Specifies the name of the resolver. | | Description | Specifies a description for the resolver. | | Angle Conditioning |
|---|
| Symbol | Units | Default | Description |
|---|
| Number of Pole Pairs | pp |
| 1 | A gain applied to the mechanical angle of the machine, θm, before it is translated to an electrical resolver signal. Modify this parameter if the resolver is attached to a gear box rather than connected directly to the rotor. To generate resolver signals whose speed corresponds to the mechanical speed of the machine, set this value to 1. See the Resolver Model Equations for more information. | | Angle Offset | θOffset | Degrees | 0° | Offset from the mechanical angle of the machine θm. | | Reverse Speed |
|
| Disabled | Reverses the direction of the resolver when enabled. | | Gain Configuration |
| Symbol | Units | Default | Description |
|---|
| Sine.Sine Gain | Sin.Sin |
| 0.999985 | Sine gain applied to the Sine output signal. See the Resolver Model Equations for more information. | | Sine.Cos Gain | Sin.Cos |
| 0 | Cosine gain applied to the Sine output signal. See the Resolver Model Equations for more information. | | Cos.Sin Gain | Cos.Sin |
| 0 | Sine gain applied to the Cosine output signal. See the Resolver Model Equations for more information. | | Cos.Cos Gain | Cos.Cos |
| 0.999985 | Cosine gain applied to the Cosine Output signals. See the Resolver Model Equations for more information. | | Excitation Conditioning |
| Symbol | Units | Default | Description |
|---|
| Sampling Frequency | Ts | MHz | 1MHz | The frequency at which the Excitation Carrier signal is sampled to determine the Sine and Cosine outputs. See Resolver Excitation Signal for more information. | | Phase Delay | Tpd | microseconds | 0us | Creates a phase delay in the output Sine and Cosine signals. This is used to simulate a physical delay in non-ideal resolvers. |
Resolver Model DescriptionA resolver is a sensor that provides feedback about the angular position and velocity of a rotating component, such as the rotor of an electrical motor. 
Figure 1. An example of a operating resolver where a sinusoidal excitation signal is input into the resolver and the result is two output signals, Sine Output and Cosine Output During operation, a sinusoidal excitation signal is provided to the resolver. The resolver modulates the input excitation signal to produce two outputs representing sin(x) and cos(x), where x is the angle of the rotor. From the sin(x) and cos(x) signals controllers are reconstituted to calculate angular position of the machine. 
Figure 2. Sine and Cosine signals generated by a resolver with an input Excitation sinusoidal signal.
Resolver Model EquationsThe resolver model outputs are calculated using the following sets of equations:
| Mathblock |
|---|
| anchor | SineOutput |
|---|
| alignment | center |
|---|
| Sine \; Output = [Sin.Sin*sin(pp(\theta_m - \theta_{Offset})) + Sin.Cos * cos(pp * \theta_m - \theta_{Offset}))] * Excitation |
| Mathblock |
|---|
| anchor | CosineOutput |
|---|
| alignment | center |
|---|
| Cosine \; Output = [Cos.Sin*sin(pp(\theta_m - \theta_{Offset})) + Cos.Cos * cos(pp * \theta_m - \theta_{Offset}))] * Excitation |
Where Sin.Sin, Sin.Cos, Cos.Sin, and Cos.Cos represent gains that are applied to simulate a non-ideal resolver. To simulate an ideal resolver, set the Sin.Sin and Cos.Cos gains to 1, set the Sin.Cos and Cos.Sin gains to 0, set the pp to 1, and set the θOffset to 0. This results in the following equations:
| Mathblock |
|---|
| anchor | simpleSineOutput |
|---|
| alignment | center |
|---|
| Sine \; Output = sin(\theta_m) * Excitation |
| Mathblock |
|---|
| anchor | simpleCosineOutput |
|---|
| alignment | center |
|---|
| Cosine \; Output = cos(\theta_m) * Excitation |
Resolver Excitation SignalFor this resolver model, the excitation signal must be provided through an Analog Input channel. To confirm the index of the channel to use, refer to the pinout information for your hardware configuration in the Archived Hardware Configurations section. In most cases, the following channels are used: | Motor 1 | Analog Input 00 | | Motor 2 (if available) | Analog Input 01 |
The amplitude of the excitation signal must be within a -1V to 1V range. If inputting a signal outside this range, use the Gain parameter for the Analog Input channel to manipulate the amplitude. Also note that the input signal must not exceed the specified voltage limitations of the hardware in any case. Typically, this hardware range is -10V to 10V, although the exact value can be confirmed on the description page of the Hardware Configuration. |