Frequency converter station SPCH is designed to change the frequency and voltage of the power circuit, control the processes of start and stop, speed regulation, over-current protection and short circuit protection of 3-phase AC motors up to 200kW.
SPCH has the following features that enhance efficiency:
- Integrated basic functions: speed control, torque control, positioning function
- Intelligent auto-start for self restart after power outage
- Built into the drive inputs and outputs to adapt the drive to a particular installation
- Built-in security features for efficient implementation of security concepts
- Adjustable supply and regeneration to prevent undesirable influence on the supply network, energy return during braking and to improve the reliability of work of network at voltage fluctuations
SPCH has the following protections:
- from inclusion of commutative device at decrease of insulation resistance to a value equal to a tripping resistance not less than 30 kOhms;
- from overload and short circuit currents;
- against impermissible heating of the conveyor’s drives;
- against breakdown of the drives;
- against autoswitch at short (up to 0.1) increase of the line voltage to 150% of UH;
- zero protection;
- against the loss of control (as open or short circuits in the remote control).
Features according the reliability and maintainability:
- Minimum duration of SPCH work up to failure is not less than - 3000 hours;
- All the components of the devices included in the SPCH are available for replacement without additional removal and dismantling of structures, which are mounted components.
Electrical scheme of the frequency converter station provides:
- voltage conversion 660V frequency 50Hz of the supply circuit into the frequency 12.5-100 Hz and voltage 0-690V on the consumer;
- bumpless connection to the rotating motor technological installation;
- control of discrete and analog signals;
- communication via Profibus or PROFINET with the control system;
- synchronizing of some SPCH between themselves on a high-speed fiber bus Simolink;
- display of technological parameters and ability to control the operation of the SPCH using operator panel;
- protection against inadvertent switching of the taps and at short (up to 0.1) increase of the line voltage up to 150% of Un;
- protection against leakage in the output circuit;
- blocking of the contactor after tripping of overcurrent protection devices, control of isolation and thermal protection;
- signaling about overload, short circuit, earth fault in the power circuit, motor temperature control, as well as the loading condition;
- additional outlets .
Frequency converter station is designed to operate in following conditions:
- • underground workings of mines, including salt, ventilated by the fresh air stream through the common shaft depression, in which by "Safety rules at designing by underground mining of salt deposits of the Republic of Belarus" allowed the usage of electrical equipment in mine normal performance;
- atmosphere type II industrial according to the GOST 24754-81;
- atmospheric pressure (84,0-106,7) kPa;
- air dustiness less than 500 mg/m3;
- altitude above sea level less than 1000m and depth no more than 1000m below the sea level;
- climatic construction U5 according to the GOST 15150-69, but the lower operating temperature of air during the operation +10 º C and the upper limit of the relative humidity of (98 ± 2) % at a temperature of ( 25 ± 2 ) º C.