Metal-clad rectifier semiconductor substations KVPP

Metal-clad rectifier semiconductor substations (hereinafter KVPP) are used for power supply of 230 V DC consumers, DC power supply of industrial plants workshop networks, including electric drive.

KVPP includes rectifier units of V-TPED series (converter sections + RESIBLOC® transformers), cabinets with automatic equipment, busbar bridges.

Main specific features:

production of KVPP rectifiers with 3-phase neutral rectification circuit and paralleling reactor, as well as 3-phase bridge rectification circuit to satisfy any Customer's requirements;
rectifiers successfully passed type tests in IPH Institut test center (Berlin, Germany) and meet EN 50328 and IEC 60146-1-1 standard requirements;
rectifier protection, control and diagnostics system ensures monitoring of each diode parameters in dynamic mode during rectifier operation, as well as event logging, visualization of temperature and voltage distribution, and other diode parameters.

high reliability and safety

up-to-date control and diagnostics system

compactness and serviceability

Key benefits:

innovative circuit and process design solutions;
microprocessor-based protection, diagnostics and control system, Web interface availability;
minimum maintenance requirements;
minimum diode replacement operations;
rectifier power part is made using the technology of maintenance-free contact joints;
monitorable force of diode pressing to the cooling units due to calibrated elements in the power assemblies;
long lifetime;
low maintenance costs.

Application fields:

industrial enterprises workshop DC networks.

CONVERTING SECTION
RESIBLOC® TRANSFORMER
PROTECTION AND CONTROL SYSTEM
CABINETS WITH AUTOMATIC EQUIPMENT

Power diodes

Power pill diodes 2500 А, 25th grade, are applied in the rectifier converting sections. Two diodes are connected in series in each rectifier arm for more reliability and lifetime prolongation. Forced current division in parallel paths is carried out due to the efficient magnetic dividers providing current division between parallel paths no less than 5 %.

Overvoltage protection

In the rectifier converting sections semiconductor power devices are protected against internal and external switching overvoltage by RC circuits and varistors.

Galvanic isolation boards

Galvanic isolation boards carry out protection against overvoltage due to RC circuits, generate data for analysis by the diagnostics system controller.

Pluton supplies modern dry transformers with RESIBLOC® windings, capacity from 630 kVA, with various combinations of high (HV) and low (LV) voltages. Transformers have original design of HV and LV windings that are made of wire and foil. Windings are capsulated by fiber-glass string soaked in epoxy.

Key transformer benefits:

fail-safe (reliable) operation under conditions of increased pollution, high humidity (in highly contaminated and humid environment), at low temperatures;
dynamical stability of windings to mechanical loads is 650-750 N/mm²;
conformance to the basic transformer equipment standards IEC 60076-11 and VDE 0532;
low noise level;
fire safety and environmental compatibility, self-damping in case of influence of external flame or electric arc, with no emission of toxic gases. All materials are non-flammable and flame-resistant;
availability of vibration damping devices;
winding and magnetic core temperature monitoring;
«cold» start with maximum load;
minimum maintenance requirements;
enhanced resistance to dynamic loads in case of overloading (under overloads) or short-circuit failures.

The system is based on B&R (Austria) industrial controller 4PPC70 (with colored HMI panel) providing each diode parameters monitoring in dynamic mode during rectifier operation, diagnostics according to "breakdown", "overheating", "parameters derating", “no connection" criteria, as well as additional parameter "diode fault" for the circuits without parallel branches of diodes. These criteria diagnostics allows to significantly increase the period of rectifier trouble-free operation for more than 80000 hours (9 — 10 years).

The system also provides:

control of diode heating temperature;
protection against rectifier and transformer overheating;
event logging;
communication with the upper level (SCADA system);
visualization of all necessary information on the color touch-screen display (power single-line diagram and status of rectifier (on/off);
diode status; rectified current, voltage, temperature, diode parameter value; warning and emergency messages).

Cabinets with automatic equipment are provided for power supply and protection of 230 V DC circuits of iron and steel works crane substations.

Configuration:

SHLA — line units cabinet;
SHVA — incoming units cabinet;
SHSA — section units cabinet.

Cabinets with automatic equipment include circuit-breakers of the leading European manufacturers (ABB, Schneider Electric) and have the following advantages: