SU1086541A1 - Method for matched control of first and second thyristor controllers of active loads - Google Patents

Description

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The invention relates to methods for coordinated control of AC consumers using semiconductor (thyristor) regulators and can be used in industrial electric heaters, co-5 resistances, various high-precision temperature regulators.

There is a known method of coordinated control of the first and second thyristor regulators of active loads, "e containing a pair of load elements and terminals connected in parallel to the connected thyristors between the elements of the load and the terminals, by changing the control angles of the thyristors Cl.

The disadvantages of this method are the low power factor with deep regulation and the high level of the Highest harmonics of the current generated by thyristor controllers in the supply network.

The purpose of the invention is to improve the energy performance by increasing the resulting power factor with independent regulation of the power consumption of each load between 0-0.5 and 0.8-1.0 P ". The goal is achieved by the method of coordinated control first and second thyristor regulators of active loads, zo containing between the load elements and terminals for connecting the power supply network of a pair of parallel-connected thyristors, by changing the angles of control of the thyristors, angles, s the control of the thyristors of the second controller at an odd period of the supply voltage is set to f at 5 G, is., O at P270.5 Rc, while changing the control angles of the thyristors primary 0 of the controller is carried out on an odd voltage period, and at an even period of the mains voltage, the control angles of the thyristors of the first controller are set equal to 45 s at P 0.5 P and oL O at PT 0.5 P, while changing the control angles of the second regulator thyristors on an even stress period continuously.50

Figure 1 shows the functional diagram of the device that implements the invention; in Fig.2, the current diagram, the first (Fig.2 "), the second (Fig.26) load and the current network (Fig. 2 a) for the case of P O, 5 Pc and P2 0.5 PH loadings 1 and 2 (Fig. 1) are connected in series with anti-parallel thyristors 3 and 4 of the First regulator and thyristors 5 0 6 of the second regulator between the terminals for connecting the power supply network of the winding current. On thyristors 3-6 with the help of formers 7-10, control pulses are applied, the phase of which is 65

these are determined by the control systems 11 and 12 and the synchronization unit 13.

Each of the regulators provides independent control of the power consumption of the corresponding load, which is provided by the control signals Vynfff ypp2 which are supplied to the corresponding control system.

In the control system, every half-period for the first regulator is in odd periods, for the second - in even-numbered voltage is formed, which is then compared with the corresponding control signals. As a result, the control pulses j are formed, the phase of which determines the angles of the is4. control thyristor controllers in accordance with a given load of each controller. At the same time, in even periods for the first controller and in odd periods for the second, with the required load power less than 0.5 PH, control pulses are not formed (ci F and otj li} When the required load power is greater than 0.5 P, right-angled impulses that ensures the angles of unlocking thyristors are equal to S O and O

The synchronization of the operation of the control system is carried out by the unit 13, which, in turn, is synchronized by the supply voltage f.

Let, for example, the resistances of loads 1 and 2 are such that the power consumed by each load is less than half the maximum. Then, during an odd period of current of the supply network, the control system 11 and the formers 7 and 8 unlock the thyristors 3 and 4 with the corresponding angles otl, the controls, while the control angles ci of the thyristors 5 and 6 are set by the control system 12 and the formers 9 and 10 equal to Л ( Fig. 2csi), and in the next even period by the control system 12 and the formers 9 and 10, the thyristors 5 and 6 are unlocked with the corresponding control angles 2 t, the control angles of the thyristors 3 and 4 by the control system 11 and the adjustor 7 and 8 are canceled equal to t. .

The total phase current of the network i is equal to the sum of the currents of the first (i) and second (ij) loads (figure 2c). As can be seen (Fig. 2-8), in each of the periods of the supply voltage, the thyristors switch the current of one of the loads (first or second), which reduces the resulting negative effect of the thyristor regulators on the supply network and other consumers. With a power consumption of more than half of the maximum thyristors 3 and 4 of the first controller in the second period and

thyristors 5 and b of the second regulator. in the first period, they are unlocked at natural switching angles (d. "(0), i.e. in this case, the current of one load is switched in each of the network periods. For example, at half the power consumed by each of the loads, the results

power is equal to one and the level of higher harmonics of the network current is zero.

The positive effect of the invention is provided by an increase in the resulting power factor and a reduction in the negative regulators on the power supply network and other electrical consumers.

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Claims (1)

THE METHOD OF THE AGREED CONTROL OF THE FIRST AND SECOND THYRISTOR REGULATORS OF ACTIVE LOADS, containing between the load elements and the terminals for connecting the supply network a pair of counter-parallel connected thyristors, by changing the control angles of the thyristors, which consists in that, in order to improve energy performance by increasing energy performance by increasing the resulting power factor with independent regulation of power consumption by each load in the range of 0-0.5 and 0.8-1.0 P _n , the control angles of the thyristors of the second controller n in an odd period, the voltage of the supply network is set equal to £ 1 = Y for P_ <0.5 P _n and cij = 0 for ² P ₂ 7 0.5 P _n , while changing the control angles of the thyristors · of the first regulator is carried out on an odd period voltage continuously, and on an even period of the supply voltage, the control angles of the thyristors of the first regulator are set equal to С = Y at Р ₁ <0.5 Рц and е £ * = 0 at R., 7 0.5 while changing the control angles, the thyristors of the second the regulator is carried out on an even period of voltage continuously. —► (with FIG.)