SU853765A1 - Converter control device - Google Patents

Description

The invention relates to electrical engineering and can be used for digital control of converters operating on AC power. Devices for digital control of the valve switching angle are known, comprising a clock pulse generator, a clock pulse counter, zero organs, an analog input signal converter into a code, code comparison blocks, and controllers ' 1X pulses ij. A disadvantage of the known devices is their complexity. The device closest to the present invention is a converter for transducer, containing for the second phase of the network a connection with a nullorgan and an emeit I, the outputs of which are connected respectively to the HONly setup and the counting inputs of the counter of clock pulses clock pulses connected to one of the inputs of the element I, the other input of which is connected to the output of the clock counter C 23 The disadvantage of the device is the dependence of the switching angle in Pick it from the frequency of the web. From the formula, the definition of the angle of inclusion is: where I am -% and% is the frequency of the network; ff - frequency of genes | the clock clock tgHayt№COB follows that when the network frequency changes, the angle of on / lt of ct switches changes. Chain invented | - improving the accuracy of angle of incidence. It is achieved that a device for flip-flops (a converter, for each phase of the network, a null-organ and an element I connect to it, whose gates are connected respectively to the installation and counting inputs of the clock counter, the control signal source and the analog-clock-controlled pulse generator connected to one of the inputs of the element And, the other input of which is connected to the output of the clock counter, is equipped with a phase detector, a filter and a control unit, and the control signal source and the phase detector is connected via pin to the inputs of the multiplication unit, its output is connected to the clock counter, and the inputs of the phase detector are connected to one of the phase bus of the network and to the output of the clock generator.

The drawing shows the functional scheme of the device.

The device contains zero-organs 1, elements AND 2, a counter of 3 clock pulses, an adjustable oscillator 4 clocks of pulses, a multiplier 5, a control signal source 6, a filter 7 and a phase detector 8.

The device works as follows. When a voltage passes through zero in any phase of the network, the zero-authority 1 of the corresponding control channel issues a pulse that arrives at the set input of the counter 3 and sets it to its initial state. From the output of counter 3 to one of the inputs of the element I 2, a signal is sent that permits active clock pulses from the generator's 4 output to the counting input of counter 3. The counter summarizes these pulses and, when it is filled, generates a signal to turn on the corresponding converter valve. At the same time, a signal is removed that permits the passage of clock pulses to the counting input of the counter. Through the half-period of the supply voltage, the entire cycle is repeated.

An adjustable 4-clock pulse generator is included in the phase locked loop, containing a phase detector 8, a filter 7, a block 5 multiplying. The voltage at the output of the multiplier is equal to the product of the voltages i, π and uij, where, 0 is the voltage of the control signal source, and is the voltage at the output of the filter 7. Therefore, the pulse frequency from the generator 4 is determined by proportional to the product of voltages. and Of, and is set equal to fj. N fc, and N 1,2,3, ... is an integer. With such a dependence of .fp on f from the above expression for the valve turn-on angle, the term fp falls out, as a result of which it ceases to depend on the frequency of the supply network.

Thus, the converter control device is not sensitive to changes in the frequency of the supply network, as a result of which the control accuracy is improved.

Claims (2)

Invention Formula A device for controlling a converter, containing for each phase of the network, a null organ and an element I connected to it, the outputs of which are connected respectively to the installation and counting inputs of the counter of clock pulses, the source of the control signal and the clock pulse generator controlled by the analog signal, connected to one of the inputs of the element I, the other input of which is connected to the output of the clock counter, characterized in that, in order to improve the control accuracy of the switching angle, it is equipped with a phase detector A filter and a multiplier unit, the control signal source and the phase detector are connected via a filter to the inputs of the multiplier unit, its output is connected to a clock counter, and the inputs of the phase detector are connected to one of the phase bus networks and to the clock generator output. Information sources, taken into account during the examination 1. SSSE copyright certificate  465704, class H 02 R 13/16, 1975. 2. USSR author's certificate  641604, cl. H 02 M 1/08, 1979.