### Resolver Configuration Page

In the System Explorer window configuration tree, expand the Power Electronics Add-On custom device and select Circuit Model >> PMSM BLDC >> Resolver to display this page.  Use this page to configure the Resolver sensor model.

### Resolver Channels

This section includes the following custom device channels:

Channel Name

Symbol

Type

Units

Default Value

Description

SineSinOutput
0Sine signal generated by the resolver. When combined with Cosine, can be used to determine the machine's position.
CosineCosOutput
0Cosine signal generated by the resolver. When combined with Sine, can be used to determine the machine's position.
Carrier
Output
0

The Excitation signal used to calculate Sine and Cosine outputs as defined in equations  and .

AngleθresolveOutputDegrees0

The angle the resolver is "resolving," defined as

 If this signal is routed to a Waveform Channel or an Analog Output Channel, its value is expressed in Turns.  The signal ranges in value from 0 to 1, with 1 representing a full rotation.

The following VeriStand channels are displayed under the Advanced section when the Enable Resolver Parameters as Channels option is enabled on the Resolver configuration page.

Channel Name

Symbol

Type

Units

Default Value

Description

Angle Offset

θOffsetInputDegrees0° (value defined in the Resolver Configuration page)

When the Enable Resolver Parameters as Channels checkbox is checked, this value describes the offset from the mechanical angle of the machine, θm.

This value can be modified while the simulation is running.

Carrier Phase Delay

TpdInputSeconds0s (value defined in the Resolver Configuration page)

When the Enable Resolver Parameters as Channels checkbox is checked, this value creates a phase delay in the output Sine and Cosine signals.  This is used to simulate a physical delay in non-ideal resolvers.

This value can be modified while the simulation is running.

Cosine Cosine Gain

Cos.CosInput
1 (value defined in the Resolver Configuration page)

When the Enable Resolver Parameters as Channels checkbox is checked, this value applies a Cosine Gain to the Cosine Output signals. This value must be a number between 0 and 1. See the Resolver Model Equations for more information.

This value can be modified while the simulation is running.

Cosine Sine GainCos.SineInput
0 (value defined in the Resolver Configuration page)

When the Enable Resolver Parameters as Channels checkbox is checked, this value applies a Sine Gain to the Cosine Output signals. This value must be a number between 0 and 1. See the Resolver Model Equations for more information.

This value can be modified while the simulation is running.

Number of Pole PairsppInput
1 (value defined in the Resolver Configuration page)

When the Enable Resolver Parameters as Channels checkbox is checked, this value applies a gain 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.

This value can be modified while the simulation is running.

Sine Cosine GainSin.CosInput
0 (value defined in the Resolver Configuration page)

When the Enable Resolver Parameters as Channels checkbox is checked, this value applies a Cosine Gain to the Sine Output signals. This value must be a number between 0 and 1. See the Resolver Model Equations for more information.

This value can be modified while the simulation is running.

Sine Sine GainSin.SinInput
1 (value defined in the Resolver Configuration page)

When the Enable Resolver Parameters as Channels checkbox is checked, this value applies a Sine Gain to the Sine Output signals. This value must be a number between 0 and 1. See the Resolver Model Equations for more information.

This value can be modified while the simulation is running.

Speed Sign
Input
Clockwise (value defined in the Resolver Configuration page)

When the Enable Resolver Parameters as Channels checkbox is checked, this value determines the speed sign based on the rotation of the resolver as follows:

• Clockwise - The resolver outputs a positive speed when the machine rotates clockwise.
• Counter Clockwise - The resolver outputs a positive speed when the machine rotates counter clockwise.

This value can be modified while the simulation is running.

### Resolver Model Description

A 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 Equations

The resolver model outputs are calculated using the following sets of equations:

 Sine \; Output = [Sin.Sin*sin(pp(\theta_m - \theta_{Offset})) + Sin.Cos * cos(pp * \theta_m - \theta_{Offset}))] * Excitation

 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:

 Sine \; Output = sin(\theta_m) * Excitation

 Cosine \; Output = cos(\theta_m) * Excitation

Depending on the selected Hardware Configuration, some resolvers allow for their excitation to come from an external source and/or some excitation signals can come from a simulated circuit.  Typical excitation signals are sinusoidal and greater than 1 kHz frequency.