Laboratory work № 1.1 Research of working modes of rectifying device (of single-phase bridge scheme of rectification and smoothing filters)

1 Purpose of the work

Learning of principles of structure, functional and schemo-technical building and functioning of rectifying devices, research of their main characteristics and peculiarities of their work.

Experimental verification of calculated results of basic electro-technical values and indicators of single-phase bridge rectifier.

Experimental research of filtering properties of smoothing filters of rectifiers

Studying of methodic of experimental defining of basic characteristics of bridge rectifier, working on different types of loads

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 – 129.

2.2 Электропитание устройств связи: Учебник для вузов / А.А.Бокуняев и др.; Под ред. В.Е.Китаева – М.: Радио и связь, 1988. – С. 87–137.

2.3 Электропитание устройств связи: Учебник для вузов / О.А. Доморацкий и др.; – М.: Радио и связь, 1981. – С. 79–138.

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.

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3 Description of laboratory stand

Given laboratory stand (pic. 3.1) is aimed for researching of the bridge scheme of rectifier(Grec`s scheme) on 5 different types of loads on the rectifying block: on active load – k = 1; on inductive load – k = 2; on capacity load – k = 3; on Г-type LC-filter k = 4; на П-type CLC-filter – k = 5. Short description of researched schemes is placed in the table 3.1.

Picture 3.1 – Laboratory stand

Laboratory stand contains:

• Source of sinusoidal voltage G1;

• transformer ТV1;

• rectifying block RF – block of semiconductor diodes VD1…VD4;

• rectifying filter – elements C1, C2, L1;

• regulated resistance R_L of the load circle;

Table 3.1 – Description of researched schemes
k	Designation in stand	Description	№ pic.
1	Active load	Scheme of rectifier with out rectifying filter– with active load. Elements L1, C1 and C2 are not used.	3.2
2	Inductive filter	Scheme of rectifier with active-inductive load. Elements C1 and C2 are not used.	3.3
3	Capacity filter	Scheme of rectifier with active-capacitive load. Elements L1 and C2 are not used	3.4
4	Г-type filter	Rectifier’s work with Г-type LC filter. Capacitor C2 is not used.	3.5
5	П-type filter	Rectifier`s work with П -type LC filter.	3.6

• switch SW1 of the resistance R_L of the load circle;

• four-beam oscilloscope – “Осциллограф”;

• voltmeter PV1 of the voltage U₁ of primary transformers winding ТV1;

• amperemeter PA1 of the current I₁ of primary transformer’s winding ТV1;

• voltmeter PV2 of the voltage U₂ of secondary transformer’s winding ТV1;

• amperemeter PA2 of the current I₂ of secondary transformer’s winding ТV1;

• voltmeter PV3 of output voltage – voltage U₀ of the load circle R_L;

• amperemeter PA3 of the current I₀ of the load R_L.

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…VD4); rectifying filter L1, C1, C2 (depending on researched scheme) and resistance of the load R_L, which can be switched off by the switch SW1. The list of elements of laboratory stand is represented in the table 3.2.The output voltage of the generator G1 and the resistance of the resister’s load R_L are put on the panel of operative regulations.

Таble 3.2 – Contant of laboratory stand

Pos.	Type of element	Regulated parameters				Comment
		The parameter	min.	max.	Unit of measurement
G1	Generator of sinusoidal voltage	Output voltage	198	242	V	Effective value, operative regulation
		frequency	50	400	Гц
TV1	Transformer	Transformation coefficient	5	15
VD1	Diode
VD2	Diode
VD3	Diode
VD4	Diode
L1	Throttle (Дроссель)	Inductance	0,01	10	Гн	Only for pictures 2, 4, 5
C1	Capacitor	Capacitance	50	104	мкФ	Only for pictures 3, 4, 5
C2	Capacitor	Capacitance	50	104	мкФ	Only for picture 5
Rн	Resister	Resistance	1	100	Оhm	Operative regulation
SW1	Switch	State	off	on		Switch of the load
PV1	Voltmeter					Effective value
PV2	Voltmeter					Effective value
PA1	Amperemeter					Effective value
PA2	Amperemeter					Effective value
PV3	Voltmeter					Average value
PA3	Amperemeter					Average value
P0	Control point

Effective value of the voltage U₁ and current I₁ of primary transformer’s winding ТV1 is controlled by the voltmeter PV1 and ampermeter PА1. Effective value of the voltage U₂ and current I₂ of secondary transformer’s winding ТV1 is controlled by the voltmeter PV2 and ampermeter PА2. Average value of the voltage U_н = U₀ and current I_н = I₀ of the load R_L 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 divided into the parts of the period of the given generator and is 0,1…100 periods/screen. List of control points of the oscilloscope is given in the table 3.3. Internal memory of the oscilloscope is enough for saving of the last period of simulation.

Table 3.3 – Researched parameters

Notation	Oscillograms of electrical processes
ТV1, U1	Voltage u1(t) of primary transformer’s winding ТV1
TV1, I1	Current i1(t) of primary transformer’s winding ТV1
TV1, U2	Voltage u2(t of secondary transformer’s winding ТV1
TV1, I2	Current i2(t) of secondary transformer’s winding ТV1
VD1, U	Voltage uVD1(t) on the diode VD1
VD1, I	Current iVD1(t) of the diode VD1
VD2, U	Voltage uVD2(t) on the diode VD2
VD2, I	Current iVD2(t) of the diode VD2
VD3, U	Voltage uVD3(t) on the diode VD3
VD3, I	Current iVD3(t) of the diode VD3
VD4, U	Voltage uVD4(t) on the diode VD4
VD4, I	Current iVD4(t) of the diode VD4
Rн, U	Voltage uн(t) on the load RL
Rн, I	Current iн(t) of the load RL
Р0 U	Voltage uВ(t) on the output of rectifying block
Р0 I	Output current iВ(t) of rectifying block
C1, U	Voltage uС1(t) on the capacitor С1
C1, I	Current iС1(t) of the capacitor С1
C2, U	Voltage uС2(t) on the capacitor С2
C2, I	Current iС2(t) of the capacitor С2
L1, U	Voltage uL1(t) on the throttle L1
L1, I	Current iL1(t) of the throttle L1

Picture 3.2 – Scheme of rectification with active load (k = 1)

Picture 3.3 – Scheme of rectification with inductive character of the load (k = 2)

Picture 3.4 – Scheme of rectification with active-capacitive load (k = 3)

Picture 3.5 – Scheme of rectification with Г-type LC filter (k = 4)