Question:Which connection options for temperature sensors are available, which temperature sensor types can be used and which settings are required?
Answer:
i950, i750, i700:
In principle, all device series enable the evaluation of different temperature sensor types. Some device series have additional options for connecting temperature sensors.
Contacting variants for temperature sensors:
- encoder input (X7/X8)
- directly at the PTC input (T1, T2)
- connection within the motor on the OCT encoder. The detected Resistance value is thereby via the digital interface HIPERFACE DSL to the inverter.
1. Encoder input (X7/X8):- devices: i950 with plugged-in encoder module (resolver, encoder), i750 and i700
- Connection for continuous temperature sensors (PT1000, KTY) for temperature-dependent adaptation of the motor model parameters.
- PTC temperature sensor or thermal contact opener (TKO):
These ssimple temperature sensors can be evaluated when the user-specific characteristic curve is parameterized, but the connection via the encoder input (X7/X8) imay only be possible to a limited extent in practice . See the information on protection against electric shock in the following article: (201600533).
2. Directly at the PTC input (T1, T2):- Devices: all i950 and i750 devices variant OCT, see post: (202300255)
- PTC temperature sensor or thermal contact opener (TKO):
Nfor the simple temperature sensors (PTC, TKO) can be ddirectly can be connected via the PTC input (T1,T2) .
When connected via T1/T2, the evaluation is carried out via hardware using a fixed switching threshold with hysteresis, so that no sensor-specific characteristic curve needs to be parameterized.
Continuous temperature sensors, such as : PT1000 or KTY, can not be evaluated via T1/T2. 3. connection ato the OCT encoder and transmission of the resistance value via HIPERFACE DSL:- devices: i950 without an encoder module (resolver, encoder) and i750 device variant OCT.
- The OCT encoder (HIPERFACE DSL) determines the resistance value of the temperature sensor connected to the OCT encoder and transmits it to the inverter via the HIPERFACE-DSL digital interface.
- For the parameterization of the motor temperature sensor the same parameters apply as if the temperature sensor were connected via the encoder input (X7/X8)
- Correspondingly, the same temperature sensor types can be used
For contacting variants 1. and 3. (encoder input (X7/X8) or via OCT encoder):
Bexample-parameterization bwhen connecting a simple PTC or TKO:
- 0x2D49:01 = [3] | User-specific characteristic curve (characteristic)
- 0x2D49:06 = 95 °C | Temperature 1: Operating temperature reached sensibly
- 0x2D49:07 = 150 °C | Temperature 2: can be left at the factory setting
- 0x2D49:08 = 0 Ohm | Resistor 1: TKO closed --> small resistor
- 0x2D49:09 = 2225 Ohm | Resistor 2: can be left at factory setting
- 0x2D49:02 = [1] Fault | Activation of temperature monitoring
Further information:
To parameter 0x2D49:08 (resistor 1):
If the parameter value is less than 122 ohms, monitoring of the temperature sensor for wire breakage is automatically deactivated.
To PTC / TKO:
In contrast to the continuous temperature sensors (PT1000, KTY), the simple temperature sensors (PTC, TKO) are only suitable for detecting a certain temperature threshold in order to protect the motor from overtemperature.
The temperature-dependent adjustment of the motor model parameters in the motor control is not possible with PTC or TKO due to the characteristic curves not sensible. See article (200511092).
Due to the principle only two points (temperatures) of the parameterized specific characteristic curve can be used, so that for the current motor temperature (0x2D49:05) is always displayed with almost the same value:
- Thermocontact TKO closed: resistance value is 0 Ohm and the set temperature 1 is effective, regardless of the actual motor temperature.
- Thermocontact TKO open: resistance value is above resistance 2 and the monitoring responds.
Current motor temperature (0x2D49:05):
The determined current motor temperature (0x2D49:05) is used to adapt the motor model parameters. If the detected value is outside the range of -100..255 °C, a temperature sensor error is concluded and the current motor temperature is assumed to be 90°C.
Possible effects of a deviating detected motor temperature on the control behavior of the drive:
- Speed control with/without position control:
The superimposed control loops for speed and, if applicable, position compensate for the effects of the unstable position compensate for the effects of the inaccurately recorded motor temperature on the torque behavior to a large extent.
- Torque-controlled operation,
(only torque setpoint specification without further superimposed control loops):
The best torque behavior will result if the unter 0x2D49:06 set temperature the actual engine temperature corresponds. In the worst case this will result in the same behavior as without continuous temperature recording.
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