Charging and power supply units.  Main Components

CPSU includes the following functional systems:

• power circuit; 
• protection system; 
• control, indication and alarm system. 

Power part has input unit, matching and isolating input transformer which secondary windings have taps for three different voltages, contactors that switch necessary windings depending on operation mode, rectifying thyristor bridge, LC-filter. CPSU feed is performed from AC line with voltage of 380 V, frequency of 50 Hz.

Each thyristor module is installed on individual cooler. Each cooler has thermosensor for supervision of thermal conditions. 

There are several types of protection tripping CPSU upon appearance of emergency situations both in load and in CPSU: 

• protection against internal short circuits; 
• protection against external short circuits; 
• protection against internal short circuit in power transformer; 
• protection upon charging rate loss; 
• maximum tolerable output voltage protection; 
• overheating of power thyristors; 
• wrong connection of accumulator battery; 
• wrong phase interlacing of input voltage; 
• protection upon jump or disappearance of input power voltage, and also CPSU reclosing upon line recovery; 
• types of protection of supervision of control system separate elements condition; 
• protection upon failures in CPSU feeding system. 

CPSU microprocessor control system provides:

• setting of necessary operation mode, parameters, etc., by buttons of control terminal and handles (buttons) on the cabinet door with checkout of introduced values on its display (2-row 16-digit LCD); 
• processing of input analog, discrete signals and forming of control pulses by CPSU power switch, and also forming of several signals of “dry" contact type for protective circuits and indication of Customer; 
• automatic voltage supply for load upon start-up, operation and stop of CPSU according to set parameters; 
• communication through serial interface CAN with upper level system; 
• service operation modes for adjustment, repair and checkout of CPSU systems. 

All tasks of control system are performed by means of software and hardware.

Peak setting of output current and voltage in control system is set through the buttons of control terminal or corresponding switches on the cabinet door with checkout on display.

There are measuring units – voltmeter and amperemeter – located on the cabinet door for measuring of output voltage and current of CPSU.

CPSU has system of insulation resistance checkout of output busbars "+” or “-“ relative to the "earth”.