BR6000-T Dynamic Power Factor Controller — Manual

The dynamic power factor controller BR6000-T is the consequent development of the BR6000 series, now in V6. It has been designed to control thyristor modules for dynamic switching of power capacitors (for example TSM-LC). A very fast processor gives extremely short switching cycles; in addition to a switching time under 20 ms, the intelligent control principle tunes the power factor by simultaneous switching of several steps. Operation is menu-guided in plain text with symbols in 10 local languages.

Main features

• Six or 12 switching outputs (depending on the type)
• Measuring voltage 30 … 525 V (L-N) or (L-L); supply voltage 110 … 230 V AC
• 20 pre-programmed control series with self-optimised intelligent control response, plus a control-series editor
• Complete menu-guided operation and display (10 languages); illuminated graphic display 2 × 16 characters
• Four-quadrant operation; display of V, I, F, Q, P, S …; display and monitoring of temperature
• Monitoring of capacitor power values with the accessory MMI6000; storage of maximum line parameters
• Manual / automatic operation; programming of fixed stages and skipping of individual outputs
• No-voltage turn-off; error detection for various states with interference-message output
• Complete 2nd parameter set, programmable / switchable; switchboard-integrated housing 144 × 144 × 55 mm

The BR6000 is built into the front panel of a PFC cabinet: it needs a switchboard section of 138 × 138 mm (DIN 43700 / IEC 61554), is inserted from the front and fixed with the appended clamps. Only qualified technicians may insert it, observing the specified safety regulations. Before connection, check that no current flows through the leads and short-circuit the current converter. Make sure measuring voltage and current are in the correct phase position; wire the measuring-current circuit with 2.5 mm² copper leads.

The alarm contact is closed in normal operation and opens in the event of a fault; the fault is shown on the display in plain text, alternating with the standard display. Messages can be individually suppressed in expert mode 2.

• UNDER-COMPENSATED
• OVER-COMPENSATED
• OVERCURRENT
• MEASURING VOLTAGE ?
• OVERTEMPERATURE
• OVERVOLTAGE
• UNDERVOLTAGE
• HARMONICS

Operating modes

When the operating voltage is switched on, the BR6000 briefly shows its designation and software version and then goes to automatic operation. The active cos φ is always in the upper line; the connected capacitors are shown as symbols in the lower line. A closed arrow shows the control direction (connecting-in / connecting-out), an open arrow that the blocking (discharge) time is running, a double arrow the fast switching of several branches.

In automatic operation capacitor stages are connected or disconnected to reach the target power factor whenever the required reactive power exceeds the smallest stage. Pressing ENTER repeatedly shows the network parameters; after 60 s without a key the display returns to the operating status.

Press the “Operating mode” key once to enter programming. The upper line shows the parameter, the lower one the set value; ▲ ▼ change it and ENTER stores it and moves on. Press “Operating mode” to quit at any step.

A programming lock (activated in expert mode) protects against unauthorised or inadvertent changes: all parameters can be checked but not changed.

• Sequential connection — stages are connected and disconnected successively (last in, first out); each step corresponds to the smallest stage. Exact definition of the next capacitor, but long settling time and high switching frequency of the small stages.
• Loop connection — first in, first out: the stage disconnected for the longest time is connected next, giving balanced utilisation and longer life of the bank. Only for control series with groups of equal stage power; long settling time.
• Intelligent loop connection (default) — combines the network-sparing loop with a much faster settling time even for large load skips, switching several or larger groups as a function of the missing power factor; considers both the real switching frequencies and the turn-on times of the branches.
• Combined de-tuning — two adjoining equal steps share one joint choke (series 1:1:1:1, 1:1:2:2, 1:1:2:2:4:4 …); the number of activated odd steps is always ≥ the number of activated even steps.

The BR6000-T12/S has an RS485 interface: full parametrisation via PC, remote read-out of all parameters, display and logging of grid parameters with the Windows software “BR7000-Soft”, connection of accessories (remote display, data logger), and MODBUS or ASCII output. Use a shielded cable, make bus connections directly at the device, and activate the terminating resistors (DIP switch ON) for point-to-point connections.

Install the controller, program all network-specific parameters in sequence as in section 5, then set automatic operation with the operating-mode key. The BR6000 needs no maintenance if the operating conditions are observed; a functional check together with the regular check of the capacitor bank is recommended. Any intervention in the controller during the warranty period voids the warranty.

Annex 3 — coupling of two PFC systems

Two PFC systems at two transformers can be coupled without a sum current transformer: connect the two controllers via their system interface with a standard LAN cable (CAT5) and feed the “coupler switch closed” signal (24 V DC) to the external input of the master. Coupler open: both systems work independently; coupler closed: the two systems operate in parallel, avoiding mutual interaction (oscillation) on a common busbar. Programming — master: PROGRAM MODE 16 EXTERNAL INPUT: COUPLING; second controller: EXPERT MODE 19 PROTOCOL: MODBUS RTU, 20 BAUDRATE 38400, 21 ADDRESS 1.

Annex 4 — capacitor current monitoring with MMI6000

The MMI6000 measures the sum current of the PFC system with a current transformer at its power input. At each switching operation the current change is compared with the rated current of the switched capacitor; in between, the current of the complete system is monitored. If the current of a step is too low (default 60 %) it is switched off, the BR6000 shows “E” and the alarm relay operates (re-activation in manual mode); if too high (default 115 %) it is switched off and checked periodically; if the sum current is too high, stages are switched off one after another. Settings — MMI6000: coupling MMI-BR6000-T, 3-phase, 38400 baud; BR6000-T (expert mode): protocol Master-MMI, 38400, number of MMI, upper / lower limits. Smallest switching time in this mode: 200 ms.

Annex 5 — mixed dynamic compensation

Fast-changing loads are compensated dynamically and basic loads conventionally. The BR6000-T6R6 supports 6 transistor outputs plus 6 relay outputs; for more stages a hybrid system with one dynamic and one or two standard controllers is used: BR6000-T12/S as [Master Hybrid], BR6000-R12/S as [Slave Hybrid] with addresses 1 and 2, 38400 baud, connected with LAN cables and the adapter CV-1xRJ45-BR6000.

Annex 6 — Register MODBUS protocol

The register example of the MODBUS protocol is given with the interface in section 8. A detailed description of the MODBUS-protocol parameters (last version) is available on the software CD, which is included in delivery with each BR6000 device with interface (BR6000-T12/S485).

Annex 7 — Windows software BR7000-Soft and accessories

The software (CD included with BR6000-T12/S485) offers a display mode, configuration manager, grid parameter table, analysis tool and harmonics diagram. Accessories: multi measuring devices MMI6000 and MMI7000, USB-to-RS485 converter, RJ45 adapter connectors and terminal-to-RJ45 converters, and the thyristor switches TSM-LC / TSM-HV for 10 … 200 kvar, 400 … 690 V.