Rectifiers and Inverters
Rectifiers and inverters belong to the group of power converters that transform electric energy from one form to another.
Rectifiers are the most widespread type of converters and they convert alternating current (AC) into direct current (DC). They are made of semiconductor elements, diodes and thyristors. Various combinations of these elements are possible, and thus there are uncontrolled rectifiers (diode rectifiers), half-controlled (a combination of diode and thyristor) and fully-controlled (thyristor rectifiers).
They are widely used in all branches of industry, power engineering, telecommunications and railways. They are mostly used for those devices which request a high level of reliability and continuity of power supply. They are used to regulate electric machines for direct current, in electrochemical and metallurgical processes, in electrolytic processes in industry, for charging and discharging the battery and as a source of extra DC power supply to devices.
Most often rectifiers are used as a power supply for consumers and for rechargeable batteries in order to maintain the necessary battery voltage so that rechargeable batteries can take over the load in case of the failure of the voltage 3x400 / 230V 50Hz.
The most common rectifier voltage levels are 12V, 24V (e.g. power supply of PLCs and security systems); 48V, 60V (power supply of telecommunication equipment); 110V and 220V (auxiliary power supply of transformer stations, hydro and thermal power plants).
Rectifiers can be modular, in our case Enatel, CORDEX, GUARDIAN, ASPIRO and monolithic, in our case the half-controlled rectifier VEGA.
The advantages of modular design are:
- simplified maintenance and the possibility to replace the power module while still working
- easy and fast upgrade, expansion of the power of the system by adding a power module
The rectifiers that are used nowadays are fully microprocessor controlled and with the possibility of remote control and monitoring.
Inverters are electronic devices that are used for the alternating current supply. They convert direct current (DC) into alternating current (AC). Advanced inverters can have two power sources: alternating (network AC) and direct (DC).
They consist of an integrated static switch that switches the power supply of the inverter to the DC voltage in case of the alternating current failure (AC) without interruption (transfer time = 0s). In our case it is a TSI series inverter, with a number of other advantages.
There is a wide range of fields where inverters are used, such as uninterruptible power supply (IPS) systems, power supply of consumers or energy transfer from renewable resources etc. Inverters as well as rectifiers are used in all fields of industry, power engineering, telecommunications and railways.
Input DC voltages are usually the following voltage levels: 12, 24, 48, 60, 110 and 220V DC.
Output AC voltage can be single-phase and three-phase.