SIMOREG CCP производства Siemens

SIMOREG CCP limits the current that flows when inverter commutation faults occur to a non-hazardous value so that the thyristors and the associated super-fast fuses are protected. This eliminates the complex and time consuming replacement of fuses after inverter commutation faults.

Although inverter commutation faults cannot be prevented, their effects can be.

• Gear units and the driven machine are protected by shutting off the current in time before it reaches its possible maximum value in the case of a fault therefore protecting them against inadmissibly high torque surges.
• For high rated system currents, up until now, high-speed DC circuit-breakers were used to protect the fuses against rupture. By using the CCP, protection is now cost-effectively possible even for lower line currents, whereby SIMOREG CCP has the following advantages when compared to high-speed DC circuit-breakers even at high current levels:
  • Protection also for circulating currents
  • Lower system costs
  • Lower space requirements
  • No additional air reactor to reduce the current rate-of-rise when a fault occurs
  • Lower operating costs, as it requires no maintenance
  • High degree of availability

¹⁾ The current range that can be covered corresponds to the actual rated current of the SINAMICS DC MASTER. When the rated current is reduced (via parameter) then the lower value obtained applies. This means that for a SINAMICS DC MASTER with (according to the type plate) a rated current higher than 2 000 A (necessary e.g. to maintain longer specified overload times), it is possible to use the CCP if the actual rated current, specified by the parameterization, does not exceed 2 000 A. The possible overload capability of 1.8x the actual rated current can be additionally utilized.

²⁾ Definition of pollution degree 2:
Generally only non-conductive pollution occurs. However, occasionally conductive pollution can be expected for a short period of time if the electronic equipment is not operational.

SIMOREG CCP distinguishes itself as a result of the compact and space-saving design.

The line supply voltage, line current as well as the armature voltage are continually sensed in the SINAMICS DC MASTER.

A possible commutation fault (inverter commutation fault - inverter shoot-through) is detected from these quantities, which results in the following measures being initiated:

1. The firing pulses are immediately disabled in the SINAMICS DC MASTER

2. The converter sends a "turn-off command" to SIMOREG CCP (via the serial interface).

3. SIMOREG CCP turns off the thyristors by connecting the pre-charged quenching capacitors anti-parallel to all thyristors. As a consequence, the current commutates from the converter into SIMOREG CCP. The quenching capacitors are initially discharged by the currents that they accept and they are then charged with the reverse polarity. The armature current starts to decrease as soon as the voltage of the quenching capacitors has reached the value of the motor EMF. However, the armature voltage continues to increase. As soon as it has reached the limit value, resistors are switched-in, which absorb the energy fed back from the motor during the remaining time of the current reduction phase.

4. A fault message is initiated in the SINAMICS DC MASTER.

5. The SIMOREG CCP re-charges the quenching capacitors with the reverse polarity so that a new quenching operation is possible.

Each time that the line supply voltage is switched in (e.g. via a line contactor), SIMOREG CCP requires approximately 3 s until it is ready for use as the quenching capacitors must first be charged up.

After a quenching operation, SIMOREG CCP requires a certain time until it is ready for use again. The duration depends on the operations during the quenching process and immediately afterwards. On one hand, the quenching capacitors in SIMOREG CCP must be charged to the required value with the reverse polarity (approx. 10 s). On the other hand, the chopper resistors, that convert the energy into heat when the armature current is reduced, require a cooling time calculated using a algorithm in the software. Depending on the amount of energy that was dissipated, this can take up to approx. 20 min.

SINAMICS DC MASTER has setting and monitoring parameters for commissioning, operation, monitoring and diagnostics of the SIMOREG CCP. The state of the SIMOREG CCP is signaled via connectors and the triggering of the SIMOREG CCP or erroneous states are signaled using fault and alarm messages.

Data is exchanged between the SINAMICS DC MASTER and SIMOREG CCP via the serial interface.

SINAMICS DC MASTER – SIMOREG CCP

The following table lists the SIMOREG CCP units that are suitable for the particular SINAMICS DC MASTER.

This information is based on the rated unit data (taking into consideration the particular limit values) of the components and on the other hand, typical rated data for Siemens DC motors from Catalog DA 12 • 2008.

Note:
For plant and system configurations with reduced rated values (e.g. DC rating, US rating, voltage derating), under certain circumstances, suitable combinations of units can be found that are not listed in the table.

For detailed engineering and when selecting the appropriate CCP, our technical support personnel can provide you with help through the local Siemens office. Please specify the following plant or system data:

• Line supply voltages and power sections
• Required undervoltage range of the power section
• Rated motor armature voltage
• Rated motor current
• Details on the required overcurrent where necessary (magnitude, cycle duration)
• Inductance of the load (motor, cable plus if required a smoothing reactor)

Block diagram

Operation without a main contactor is not permissible.
The control voltage for the main contactor (or the circuit-breaker) must always be routed via terminal XR (connection 109 and 110) of the SINAMICS DC MASTER unit and via terminal X_Contactor (connections 4 and 5) of the SIMOREG CCP.

For applications with SIMOREG CCP, in the case of a fault, the converter or SIMOREG CCP must be able to disconnect safely the arrangement from the line supply. Further, it must be ensured that the total of the delay times of all of the switching elements in the control circuit must not exceed the time set using the corresponding parameters. When SINAMICS DC MASTER units are connected in parallel, each unit is directly connected to a SIMOREG CCP in parallel (refer to the block diagram for the parallel connection).

Block diagram for the parallel connection

1) However Russian not for SIMOREG CCP.