DC bus bulk capacitance
Certain applications will require additional DC bus capacitance. Typically extra capacitors are needed in applications with long supply cables (with high parasitic inductance or resistance) or where the power supply does not tolerate a high current ripple. Adding the extra capacitors reduces the ripple current on supply lines and therefore reduces losses as well as electromagnetic interference (EMI). For best results, the capacitors should be connected to the DC link terminals on the back of the Titan. Since this drive includes automatic precharge circuits, there is no need for additional and bulky relays or precharge resistors.
For the Titan voltage and power ratings, Ingenia recommends metallized polypropylene film capacitors (MKP), as they provide the best trade-off of capacitance, ripple current and long term reliability.
Electrolytic capacitors provide higher energy density and lower cost, however only good quality, low ESR and high current ripple current are acceptable. Current ripple of the capacitor bank should be at least 0.4 * motor rated rms current at its operating temperature. Electrolytic capacitors must have low series resistance and be prepared for high current, otherwise they may overheat and be damaged. High power density applications could be also based on ceramic capacitors, however cost would increase dramatically. Custom versions of Titan can be provided with extra DC bus ceramic capacitance.
Next there are some suggested capacitors that should be attached to the DC link terminals (not to the input supply):
| Manufacturer | Part number | Capacitance / Technology | Rated Voltage | Photo | Dimensions | Comments |
|---|---|---|---|---|---|---|
| Kemet | C4DEFPQ6380A8TK | 480 μF MKP | 400 VDC |
| Diameter 84.0 mm x 66.0 mm (height) | Good trade off of capacitance / price. Height exceeds the Titan. |
| Panasonic | EZT-VKCTYP1HA | 581 μF MKP | 450 VDC |
| 164.0 mm x 115.0 mm x 43.0 mm (height) | Height is < Titan. This makes a low profile solution. |
| EPCOS | B25655P4707K031 | 700 μF MKP | 450 VDC |
| 237.0 mm x 72.0 mm x50.0 mm (height) | - |
| EPCOS | B25655P4108K031 | 1000 μF MKP | 450 VDC | Highest capacitance option on metal film. High cost. | ||
| Cornell Dubilier Electronics (CDE) | 947D421K901BDMSN | 420 μF MKP | 900 VDC |
| Diameter 90.0 mm x 88.0 mm (height) | Good capacitance / price. Height exceeds the Titan. Recommended for 800 V version. |
| Cornell Dubilier Electronics (CDE) | 947D601K901DCRSN | 600 μF MKP | 900 VDC |
| Diameter 116.0 mm x 76.0 mm (height) | Good capacitance / price. Height exceeds the Titan. Recommended for 800 V version. |
United Chemi-Con | E37F351CPN223MFM9M | 22000 µF Aluminum electrolytic | 350 VDC |
| Diameter 89 mm x height 220 mm | Very high capacitance. 46.7 A ripple current. 4 mΩ ESR. |
| Nichicon | LNC2G123MSEJ | 12000 µF Aluminum electrolytic | 400 VDC |
| Diameter 90 mm x height 148 mm | High capacitance. 37.1 A ripple current. Comes with assembly bracket. Low cost. |
Follow these recommendations:
- Use thick, as short as possible cables between the DC bus capacitor and the Titan.
- Use the internal DC bus terminals to add the capacitance needed (see below).
- Use M3 ring terminals like Phoenix Contact to connect to the internal DC bus terminals.
