Лабораторная работа № 1.2 Research of 3-phase schemes of rectifiers
1 Purpose of the work
Study the principles of construction and operation of schemes of rectifying devices and features of their schematic implementation.
Study the principle of three-phase single-cycle and two-cycle bridge circuit of rectification. Experimental study of their characteristics and electromagnetic processes
To learn the methods of experimental determination of the main characteristics of multiphase rectifiers.
2 Литература
2.1 Электропитание устройств связи: Учебник для вузов / А.А.Бокуняев, В.М. Бушуев, А.С. Жерненко, А.Ф. Кадацкий и др.; Под ред. Ю.Д. Козляева. – М.: Радио и связь, 1998 – C. 69–106.
2.2 Электропитание устройств связи: Учебник для вузов / А.А.Бокуняев и др.; Под ред. В.Е. Китаева – М.: Радио и связь, 1988– С. 87–128.
2.3 Электропитание устройств связи: Учебник для вузов / О.А. Доморацкий и др. – М.: Радио и связь, 1981. – С. 79–120.
2.4 Китаев В.Е. и др.; Электропитание устройств связи. – М.: Связь, 1975. – С. 129–160.
2.5 Иванов-Цыганов А.И. Электропреобразовательные устройства РЭС: Учебник для вузов. – М.: Высшая школа, 1991. – С. 65–143.
3 Description of laboratory stand
Given laboratory stand (рiс. 3.1) is aimed for researching of three-phase circuits of rectification of two types(3-phase single-cyclek = 1 and 3-phase bridge circuit – k = 2) under active and inductive loads.
Short description of researched schemes is placed in the table 3.1., list of researched parameters is placed in the table 3.2, list of elements of the stand – in the table 3.3.
Laboratory stand contains:
source (generator) G1 of three-phase sinusoidal voltage;
three-phase transformer ТV1;
Rectification filter, created by throttels L1;
resistance RL of the load of the rectifier;
rectifying block RF – block of semiconductor diods VD1 … VD3 (3-phase single-cycle curcuit) and VD1 … VD6 (3-phase bridge circuit);
switch SW1 of the load RL of rectifier;
switch SW2 of the throttle L1;
four-beam osciloscope – “Осциллограф”;
voltmeter PV1 of the voltage UА of phase А of the winding of higher voltage- of the primary transformer`s winding ТV1;
ampermeter PA1 тока IА of phase А of the winding of higher voltage;
voltmeter PV2 of the voltage Ua of phase а of the winding of lower voltage – of secondary transformer`s winding ТV1;
ampermeter PA2 тока Ia of phase а of the winding of lower voltage;
voltmeter PV3 of the voltage Uн of rectifier`s load;
ampermeter PA3 of the current Iн of the rectifier`s load.
Picture 3.1 – Laboratory stand
Table 3.1 – Description of researched schemes |
|||
k |
Designation in stand |
Description |
№ pic. |
1 |
Three-phase |
Three-phase single-semi-cycle circuit (Mitkevich`s circuit). Elements VD4…VD6 are not used |
3.2 |
2 |
Three-phase bridge |
Three-phase two-semi-cycle circuit (Larionov`s circuit) |
3.3 |
Рicture 3.2 – Three-phase rectification circuit (k = 1)
Рicture 3.3 – Three-phase bridge rectification circuit (k = 2)
Laboratory stand consists of primary electro-feeding source G1, transformer ТV1, providing matching of voltage of primary electro-feeding with needed voltage of the load;, rectifying block RF VD1…VD3 or VD1…VD6 (depending on researched scheme), rectifying filter L1 and resistance of the load RL, , which can be switched off by the switch SW1. The list of elements of laboratory stand is represented in the table 3.3. The output voltage of the generator G1 and the resistance of the resister`s load RL are put on the panel of operative regulations.
Effective value of the voltage of primary UА, IА phase А and secondary Ua, Ia windings phase a of transformer ТV1 is controlled by voltmeters PV1, PV2 and ampermeters PА1, PА2. Average value of the voltageUн = U0 and current Iн = I0 of the load RL are measured by the voltmeter PV3 and ampermeter PA3.
Four-beam oscilloscope, providing observation of the voltage and currents in the different points of the scheme,is included to the set of control-measuring devices. . Synchronization of the oscilloscope is made automatically according to the work pf the generator G1,that is why the duration of the involute(развертки)is devided into the parts of the period of the given generator and is 0,1…100 periods/screen. List of control points of the oscilloscope and researched parameters is given in the table 3.2. Internal memory of the oscilloscope is enough for saving of the last period of simulation