RU2622043C2 - Control system of controlled voltage rectifier - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: controlled voltage rectifier can maintain the required value of the displacement angle ϕ₁ between a sinusoidal voltage having a frequency f₁ of the alternating voltage source to which the input terminals of the controlled voltage rectifiers (CVR) are connected, and the first harmonic of the input current of the CVR. In particular, when the CVR operates as a rectifier receiving power from the alternating voltage source (VS) and transmitting it to its DC consumers 4, the first harmonic of the input current of the CVR coincides in phase with the corresponding phase voltage of the VS, then the angle ϕ₁ is equal to 0 radians (or 0). In addition, the CVR can operate as a stand-alone voltage inverter transferring power from the DC consumer (4) DC to the VS. In this case, the first harmonic of the input current of the CVR is opposite in phase to the corresponding voltage of the VS, i.e. the angle ϕ₁ is equal to π (180). In both cases, the absolute value of the power factor consumed from the VS or entering it is 1, i.e. it has the maximum value. Apart from the CVR the control system contains the following main elements: a control device (5), a control unit (6) and measuring transducers of the input (21) and output (24) currents, and the input (22) and output (23) voltages. The control system is supplemented with a device (2) for connecting the CVR to the VS. The device (2) includes a current-limiting circuit containing a current-limiting reactor (34), as well as the first (35) and second (36) switches, and additional measuring transducers for the input current (37) and the input voltage (38) of the device (2). In addition, the control system is supplemented by an evaluation unit (7), an information display unit (8) and an additional measuring transducer (25) of the output voltage of the CVR.

EFFECT: decrease down to safe values of the current circuits of controlled voltage rectifiers arising when connecting the controlled voltage rectifiers with uncharged output capacitor to an AC voltage source at times when the voltage of the voltage source is close to its peak value, simplified, accelerated, and improved quality of the output capacitor capacity setting, inductance of the current-limiting reactor of the controlled voltage rectifiers and coefficients of the communication transmission between elements of the control device.

3 cl, 3 dwg

Description

The proposed device relates to electrical engineering, in particular to devices for converting alternating current to direct, and vice versa, direct current to alternating current using semiconductor devices: transistors and diodes in a bridge circuit.

источника переменного напряжения, к которому подключены входные зажимы УВН, и первой гармоникой входного тока УВН. В частности, когда УВН работает в качестве выпрямителя, получающего энергию от источника напряжения ИН переменного тока и передающего его потребителям постоянного тока, первая гармоника входного тока УВН совпадает по фазе с соответствующим фазным напряжением ИН, то есть угол ϕ₁ равен 0 радиан (или 0). Кроме того, УВН может работать и в качестве автономного инвертора напряжения, передающего энергию от потребителя постоянного тока к ИН. При этом первая гармоника входного тока УВН противоположна по фазе соответствующему напряжению ИН, то есть угол ϕ₁ равен π (180). В обоих случаях абсолютное значение коэффициента мощности, потребляемой от ИН или поступающей в него, равно 1, то есть имеет максимальное значение.Controlled voltage rectifiers (DC), which are also known as: active rectifiers or reversible voltage converters, are used as a rectifier to power DC consumers or, together with stand-alone inverters, as part of frequency converters. The basis of UVN is a conventional uncontrolled rectifier composed of uncontrolled diodes (D), which is now also called an uncontrolled rectifier. In the case of UVN, transistors (T) are connected in parallel with the diodes, which function as electronic switches that conduct current in the direction opposite to the direct current of the parallel connected diodes. The combination of all D and T forms a valve switch (VK). It is thanks to the specified VK device that the UVR, in contrast to rectifiers of other varieties, has a remarkable property: in a controlled mode of operation, it can maintain the required value of the angle _of shift ϕ ₁ between the sinusoidal voltage having a frequency

the AC voltage source to which the input terminals of the UVN are connected, and the first harmonic of the input current of the UVN. In particular, when an IHF operates as a rectifier, receiving energy from an AC voltage source of alternating current and transmitting it to DC consumers, the first harmonic of the input voltage of the IHF is in phase with the corresponding phase voltage of the IN, that is, the angle ϕ ₁ is 0 radian (or 0 ) In addition, the IHC can also work as a stand-alone voltage inverter, transmitting energy from a DC consumer to an ID. In this case, the first harmonic of the input voltage of the IHF is opposite in phase to the corresponding voltage of the IN, i.e., the angle ϕ ₁ is π (180). In both cases, the absolute value of the power factor consumed from or supplied to the ID is 1, that is, it has a maximum value.

To ensure the required value of the angle ϕ _{1 of the} shift between the sinusoidal input voltage of the UVN and the first harmonic of the input current of the UVR and the stabilization of the rectified voltage U _{d, the} UVR is introduced into the control system, which in addition to it also contains a control device, the output of which is connected to the VK control input , a control unit, the output of which is connected to the control input of the control device, and measuring transducers of input and output currents and voltages of UVN, the outputs of which are connected to measuring inputs of the control device.

In uncontrolled operation mode, when only VC diodes conduct current, VC transistors cannot be turned on, that is, the transition to operation in a controlled mode cannot be carried out, since the voltage drop in the open diode is applied to the transistor electrodes in the opposite direction to which the transistor goes over into a conducting state when a corresponding control pulse is applied to it.

, которая также называется несущей частотой, в сотни и более раз превосходит частоту

ИН.The input terminals of the VK are connected to the input terminals of the UVN, and the output terminals of the VK are connected to the output terminals of the UVN, to which its load and output capacitor are connected, which is a mandatory element of the UVN and is designed to perform the following three functions. Firstly, it is stabilization of the average value of the output voltage of the UHF U _d at the level required by the load of the UHF regardless of this value on the load current, and smoothing of the output voltage U _{d of the} UHF: the amplitude values of the ripple of its voltage are less than those that are acceptable for the load of the UHF. Secondly, the output capacitor prevents the uncontrolled occurrence of uncontrolled operation of the UVR, since the voltage U _{d of the} output capacitor is maintained at a level exceeding the amplitude of the sinusoidal voltage IN. Thirdly, due to the voltage U _{d of the} output capacitor, the UHF, working as a stand-alone voltage inverter using pulse-width modulation (PWM), generates a voltage at the VC input, the shape of which is a sequence of rectangular pulses with a constant amplitude equal to U _d , but with their duration varying according to a sinusoidal law. Switching frequency of these pulses

, which is also called the carrier frequency, is hundreds or more times higher than the frequency

IN

.The first harmonic of the input voltage VC balances the main part of the voltage IN. In addition to the first harmonic, the input voltage of the VC contains a number of higher harmonics, the first of which have frequencies close to the carrier frequency

.

по времени t входного тока i₁ УВН, в момент времени, соответствующий началу перехода во включенное состояние одного из транзисторов анодной группы ВК и одного из транзисторов его катодной группы, так как в этот момент времени к реактору подводится сумма напряжений ИН и выходного напряжения U_d УВН, и эта сумма равна

. В-третьих, входной реактор сглаживает входной ток УВН и не пропускает в ИН и в другие кроме УВН потребители электроэнергии, подключенные к ИН, высшие гармонические составляющие входного тока УВН, так как индуктивное сопротивление реактора для высших гармонических составляющих входного тока УВН в сотни и более раз больше, чем его сопротивление для первой гармоники, и тем больше, чем больше номер высшей гармоники.In a single-phase bridge-type IHV, between the first of the input terminals of the IOC and the first of the input terminals of the VK, series-connected measuring transducer of the input current of the IOC and the input reactor having an inductance L are connected, and the second of the input terminals of the VC and IOC are connected directly to each other. In a three-phase bridge-type I-V, three-phase I / O input terminals are connected to the three-phase ID output terminals and, through three-phase input reactors, each of which is connected in series with the input-phase input current measuring transducer, to the corresponding input terminals of the VC. Input reactors are mandatory elements of the IOC, which are designed to perform the following three functions. Firstly, the inductive reactance of the reactor ω ₁ L, where ω _{1 is the} angular frequency of the IN, determines the amplitude and phase of the first harmonic of the input current of the IHV, since the voltage drop from this current at the indicated inductive resistance is equal to the difference between the main part of the voltage of the IN and the first harmonic of the input voltage VK. Secondly, the reactor inductance L determines the derivative

in time t of the input current i _{1 of the} UHF, at the time corresponding to the beginning of the transition to the on state of one of the transistors of the anode group VK and one of the transistors of its cathode group, since at this moment of time the sum of the voltages IN and the output voltage U _d UVN, and this amount is equal to

. Thirdly, the input reactor smoothes the input current of the IHV and does not transmit to the IN and other than the IOD consumers of electricity connected to the ID the higher harmonic components of the input current of the IOD, since the inductive resistance of the reactor for higher harmonic components of the input current of the IOC is hundreds or more times greater than its resistance for the first harmonic, and the greater the greater the number of higher harmonics.

A known control system for a single-phase bridge UVN. A diagram of this I-V and the waveforms of currents and voltages in it are given in [Electrical Engineering. - In 3 books. Book II. Electric cars. Industrial Electronics. Theory of Automatic Control / Ed. P.A. Butyrina, R.Kh. Gafiyatullina, A.L. Shestakova. - Chelyabinsk: SUSU Publishing House, 2004. - 711 p., Pp. 445, 446 and 451, Figure 25.3 (analogue)]. The analogue works as follows: before connecting to the source, the voltage of the output capacitor is zero. At the command received from the control unit (CU), the process of uncontrolled charge of the output capacitor begins. Due to the negligible resistance of the diodes included in the rectifier gate switch (VC), and the lack of voltage at the terminals of the output capacitor, the initial stage of this process is equivalent to a short circuit of the voltage source (IN). As a result, the voltage at the output capacitor begins to increase. To reduce the aforementioned inrush currents, current-limiting resistors are usually included in the input circuit of the device for connecting the UVR.

The analogue works with a shift angle ϕ ₁ between the input voltage of the IHV and the current consumed from the ID equal to 0, or the current returned to the IN equal to π. The control unit (CU) delivers to the control device (CU) two arrays of specified instantaneous values of the input current of the IOC. The first of them consists of the maximum instantaneous values of this current, which slightly exceed the instantaneous values of the sinusoidal current, which coincides in phase with the input voltage of the IHV in the rectifying mode of its operation or is in phase with the input voltage of the IHV in inverted mode of its operation. The second array consists of the minimum instantaneous values of the input current of the UHF, which are slightly less than the instantaneous values of the specified sinusoidal current. At times when the value of the input current measured by the measuring transducer is equal to the value of the input current from the second array, the UE gives a command to turn on one of the transistors of the anode group VK and one of the transistors of its cathode group. After that, the input current of the UHF begins to increase. When it reaches the value included in the first array, the UU will issue a command to turn off these transistors. After that, the input current of the IOC will begin to decrease. When it reaches the value included in the second array, the process will be repeated.

The analogue has three drawbacks. The first of these is the large size of these two arrays, which requires a large amount of computational work to compile these arrays. The second drawback of the analogue is that the literature has not yet described proven practice algorithms for other shift angles ϕ ₁ not equal to 0 or π. The third disadvantage of the analog is manifested in the fact that it does not provide stabilization of the average value of the output voltage of the UVN.

Also known, free from the disadvantages of an analogue, is a control system for a single-phase bridge UVN, which is closest in technical essence to the proposed device and is selected as a prototype, a functional diagram of which and explanations are given in [Electrical Engineering. - In 3 books. Book II. Electric cars. Industrial Electronics. Theory of Automatic Control / Ed. P.A. Butyrina, R.Kh. Gafiyatullina, A.L. Shestakova. - Chelyabinsk: Publishing house of SUSU, 2004. - 711 p., P. 460, 461, figure 25.13, (prototype)]. The control system of a controlled voltage rectifier (IHF), which contains a single-phase bridge I / O device, containing a single-phase gate switch (VK), an input reactor and an output capacitor, as well as a control device, the output of which is connected to the control input of the VK, connected to the inputs by its outputs the control device, the control unit and measuring transducers of input and output currents and voltages of the IHV, and the first output of the control unit connected to the control input of the control device a narrow VHF, an output capacitor and a measuring device for output voltage of the VHF are connected between the positive and negative output terminals of the VHF, and both the first and second input terminals of the VHF are connected to the output terminals of a single-phase AC voltage source or with two phase output terminals of a three-phase AC voltage source, while the input voltage measuring transducer is connected between the first and second input terminals of the UVN, the first input terminal of the UVN is connected to the first input terminal VC through a serial connection of the input current measuring transducer of the IOC and the input reactor, and the second input terminal of IOC is connected directly to the second input terminal of VC, the positive output terminal of VC is connected directly to the positive output terminal of VC, and the negative output terminal of VC is connected to negative output terminal of VC through the measuring transducer of the output current UVN. The control unit (CU) of the prototype delivers only two quantities to the control device (CU): the specified value of the angle ϕ _{1 of the} shift between the sinusoidal input voltage of the IOC and the specified average value of the rectified voltage U _d . In addition to the positive property, which is manifested in the absence of the above disadvantages of the analogue, the prototype has two disadvantages.

The first of them is that the currents of the IHF circuits arising when the IHF with an uncharged output capacitor is connected to a source of variable uncontrolled voltage may be too large, since the input current of the IHF is, in fact, a short-circuit current of the IN to the input reactor . The inductance of this reactor is relatively small, since it should not be greater than that which ensures the achievement of the required value of the initial derivative of such a given sinusoid of the input current of the rectifier in a controlled mode of its operation, which is shifted from the sinusoidal voltage IN by a small predetermined angle ϕ ₁ . Therefore, the currents of the I / O circuits arising when the I / O with an uncharged output capacitor is connected to the ID at times when the voltage of the ID is close to its amplitude value can damage the rectifier diodes, the internal conductors of the output capacitor and the connecting wires.

The second disadvantage is the inability of the prototype to quickly adjust the capacity of the output capacitor and the transmission coefficients of the links between the elements of the control unit when changing the load parameters of the IHV, when it is necessary to adjust the value of the capacity of the output capacitor, replacing the number and capacity of the parallel connected capacitors, while achieving the necessary amplitude of ripple of the output voltage of the IO .

Changing the parameters of the output capacitor entails a change in the transfer functions of the UVN, which is the control object. Therefore, in order to provide the required static and dynamic characteristics of the control loops of the angle ϕ _{1 of the} shift between the input voltage and the current of the high voltage and to stabilize the rectified voltage U _d, it is necessary to re-configure the transmission coefficients of the links between the elements of the control unit. The required settings and adjustments of the UVN and UU parameters are made by the operator, who makes decisions based on the parameters and the oscillograms of the signals operating in the tuned system displayed with the help of an oscilloscope. The indicated parameters and arrays of instantaneous values that form these oscillograms can be obtained using additional measuring transducers of input and output currents and voltage of high voltage. Similar full-time measuring transducers, which, together with the IHF and UU, producing UHF companies, are included in one common kit with the IUU and UU, cannot be used to perform the specified tuning works, since the outputs of these transducers, designed to connect to the high-impedance inputs of the microprocessor, on the basis of which it is implemented UU, it is forbidden to use for another purpose. Thus, the performance of the indicated tuning work requires the creation of a rather complex measuring complex each time after replacing the IOC or lines that connect the IOC to the IN and to the load of the IOC, as well as after changing the load parameters of the IOC, or IN, or after changing the network structure into which Includes IN.

The task to which the invention is directed is to improve the quality indicators of work and the settings of the control system of the IOC:

- reduction to safe values of the currents of the I / O circuits arising when the I / O with an uncharged output capacitor is connected to an IN at times when the voltage of the IN is close to its amplitude value.

- addition of the control system of the IOC elements that will simplify, speed up and improve the quality of setting the output capacitor capacitance and transmission coefficients of the links between the elements of the control unit, which must be done every time after replacing the IOC or lines that connect the IOC to the IN and to the load of the IOC, as well after changes in the load parameters of the IOC, or ID, or after changes in the structure of the network, which includes ID.

The task is achieved by the fact that in the control system of a controlled voltage rectifier (RPC), which contains a single-phase bridge RCD, containing a single-phase gate switch (VK), an input reactor and an output capacitor, as well as in addition to the RPC, a control device, the output of which is connected to the control input VK, connected by their outputs to the inputs of the control device, the control unit and the measuring transducers of the input and output currents and voltages of the UVN, and to the control input of the control device by the first output of the control unit is switched on, the load of the IHF, the output capacitor and the measuring transducer of the output voltage of the IHF are connected between the positive and negative output terminals of the IHV, and both, the first and second input terminals of the IHC are connected to the output terminals of a single-phase AC voltage source or with two phase output terminals of a three-phase an AC voltage source, while the input voltage measuring transducer is connected between the first and second input terminals of the UVN, the first input the IHV press is connected to the first input terminal VC through a serial connection of the input current measuring device and the input reactor, and the second input terminal is connected directly to the second input terminal VC, the positive output terminal VC is connected directly to the positive output terminal VC, and the negative output terminal VK connected to the negative output terminal of the IHF through the measuring converter of the output current of the IHV, a device for connecting the IOC to the voltage source current (the abbreviated name of this device is UP), in which the input terminals are directly connected to the output terminals of a single-phase AC voltage source or to two phase output terminals of a three-phase AC voltage source, and the input terminals of the UVN are connected to the output terminals of the UP, which contains a current-limiting circuit, consisting of a current-limiting reactor and first and second switches, the first terminal of the first switch being connected to the first input terminal of the unitary enterprise, to the second terminal of the first switch By connecting the first terminals of the second switch and current limiting reactor, and their second terminals connected to first output terminal UP, the second output terminal of which is connected to its second input terminal directly, and the control input UP is connected to the second output of the control unit.

The task is also achieved by the fact that the computing unit and the information display unit are additionally introduced into the control system of the UVN equipped with a control unit, to the control inputs of which the third and fourth outputs of the control unit are connected respectively, an additional measuring converter of the output voltage of the UVN is also introduced, and, in addition, intended for measuring the input current and input voltage UE, additional current and voltage converters, while the input terminals of additional measuring trans Browsers of input and output voltages are connected respectively to the input terminals of the UE and to the output terminals of the UVN, the additional measuring transducer of the input current is connected by its input terminals between the first input terminal of the UP and the first terminal of the first switch, and the output terminals of all additional measuring transducers are connected one by one to the corresponding measuring the inputs of the computing unit and the information display unit, the output of which can be connected to an oscilloscope performing tion information storage device.

The stated task is also achieved by the fact that three current-limiting reactors, the first and second, are introduced in the control unit for a three-phase bridge UVN containing one for each phase, that is, three input reactors, three measuring converters of the phase input current and three measuring converters of the phase input voltage circuit breaker, as well as additional measuring transducers of input currents and voltages UE, (difference from UE single-phase UVN, in which the input and output terminals were called the first and second, for UE tripha it is advisable to call these terminals phase and zero), in each phase of the UE, between its input phase terminal connected to the phase output terminal of the three-phase IN and the output phase terminal of the UE connected to the phase input terminal of the UVN, an electrical circuit consisting of an additional measuring circuit is connected converter of input current unitary enterprise, first and second switches and current-limiting reactor, and the first input terminal of an additional measuring transducer is connected to the phase input terminal of unitary enterprise current, the second input terminal of which is connected to the first terminal of the first switch, to the second terminal of which the first terminals of the second switch and current limiting reactor are connected, the second terminals of which are connected to the output phase terminal of the control unit, input terminals of each of the three additional transducers measuring the phase input voltage of the control unit are connected to the corresponding phase input terminals of the unitary enterprise and to the input terminal zero of the unitary unit connected to the neutral terminal of the winding of a three-phase AC voltage source or to skusstvennomu zero power system, which includes the voltage source.

Distinctive features of the proposed solution perform the following functional tasks:

The sign "... a device has been introduced into the UVN control system for connecting the UVN to an AC voltage source (the abbreviation of this device is UP), in which the input terminals are directly connected to the output terminals of a single-phase AC voltage source or to two phase output terminals of a three-phase AC voltage source, and the input terminals of the UVN - to the output terminals of the UP, which contains a current-limiting circuit consisting of a current-limiting reactor, the first and second switches, the first the first switch clamp is connected to the first input terminal of the control unit, the first terminals of the second switch and current-limiting reactor are connected to the second terminal of the first switch, and their second terminals are connected to the first output terminal of the control unit, the second output terminal of which is connected directly to its second input terminal, and the control input The control unit is connected to the second output of the control unit ”, provides a reduction to safe values of currents arising in the I / O circuits when the I / O with an uncharged output capacitor is connected to an ID. Such a result is achieved, in particular, when the condition is fulfilled: the largest amplitude of the input current of the UE, when connected to the ID, should not exceed the amplitude of the input current of the IHV in its nominal controlled mode. In this case, the use of a current-limiting reactor is better than the use of a current-limiting resistor, which is a traditional solution to reduce inrush currents. When using a current-limiting reactor, power losses in an additional current-limiting element are many times reduced and the charge time of the output UVN capacitor in an uncontrolled mode of its operation is reduced.

The sign "... in the control system of the UVN equipped with a control unit, a computing unit and an information display unit are additionally introduced, to the control inputs of which the third and fourth outputs of the control unit are respectively connected, an additional measuring converter of the output voltage of the UVN and, in addition, designed to measure the input current and input voltage UP, additional current and voltage converters, while the input terminals of additional measuring transducers of input and output n of voltages are connected respectively to the input terminals of the UE and the output terminals of the UVN, the additional input current measuring transducer is connected by its input terminals between the first input terminal of the UP and the first terminal of the first switch, and the output terminals of all additional measuring transducers are connected one at a time to the corresponding measuring inputs of the computing unit and information display unit, the output of which can be connected to an oscilloscope that performs the function of an information storage device provides a simpler, faster and improving the quality of output settings capacitance, inductance input UVN reactor and transmission coefficients of connections between elements providing W through the tuner-operator in a visual form the information required about the parameters and waveforms of input and output currents and voltages UVN.

The sign “... in the control unit for a three-phase bridge UVN containing one for each phase, that is, three input reactors, three measuring transducers of the phase input current and three measuring converters of the phase input voltage, three current-limiting reactors, the first and second circuit breakers, and additional measuring transducer of input currents and voltage UE, and in each phase UE between its input phase terminal connected to the phase output terminal of the three-phase IN and the output phase terminal UE, under connected to the phase input terminal of the UVN, an electric circuit is connected, consisting of an additional measuring transducer of the input current of the unitary unit, the first and second switches and a current-limiting reactor, while the first input terminal of the additional measuring transducer of the input current, the second input terminal of which is connected to the phase input terminal of the UP to the first terminal of the first switch, to the second terminal of which the first terminals of the second switch and the current-limiting reactor are connected, the second we are connected to the output phase terminal of the UPS, in addition, the input terminals of each of the three additional transducers measuring the phase input voltage of the UPS are connected to the corresponding phase input terminals of the UPS and to the zero input terminal of the UPS connected to the neutral terminal of the winding of a three-phase AC voltage source or artificially zero power system, which includes the source voltage "can improve the performance of control systems angle φ ₁ between the sinusoidal shear in UVN odnym voltage and the first harmonic of the input current UVN in each of its three phases due to more accurate measurement of each of the input voltages UVN that access is provided to the zero point of the electrical system, to which is connected UVN.

The technical result that is achieved when solving the problem is expressed in the following. Distinctive features of the invention provide an improvement in the quality of performance and tuning of the control system of the IOC due to:

- reduction to a safe value of the currents of the I / O circuits arising when the I / O with an uncharged output capacitor is connected to an ID at a time when the voltage of the ID is close to its amplitude value;

- an additional control system for the UVN elements, which allowed to simplify, accelerate, and improve the quality of tuning the capacitance of the output capacitor, inductance of the input reactor, UVN, and transmission coefficients of the links between the elements of the SU.

From the foregoing, it can be concluded that the set of essential features of the invention has a causal relationship with the achieved technical result, i.e. due to this combination of essential features of the invention, it became possible to solve the problem. Therefore, the present invention is new, has an inventive step and is suitable for use.

The invention is illustrated in the drawing, where: in FIG. 1 - presents a functional diagram of a control system for a single-phase bridge UVN; in FIG. 2 - the same, but for one phase of a three-phase bridge UVN; in FIG. Figure 3 shows the input characteristics of a single-phase UHF bridge UE when using a current-limiting reactor (solid line) and a current-limiting resistor (dashed line).

The control system controlled by a rectifier 1 voltage, which is connected via a power supply unit 2 to an AC voltage source 3 (IN) and is intended to supply a direct current load 4, contains in addition to the listed elements a control device (UU) 5, a control unit (BU) 6, a computing unit (WB) 7 and information display unit (BOI) 8, to the outputs of which the inputs of the oscilloscope 9 are connected. The first, second, third and fourth outputs of BU 6 are connected to the first inputs of UU 5, BOI 8, WB 7 and to the control input of UP 2.

The first 12 and second 13 input terminals of UP 2 are connected to the first 10 and second 11 output terminals of ID 3, respectively, the first 14 and second 15 output terminals of which are connected respectively to the first 16 and second 17 input terminals of UVN 1.

UVN 1 contains a gate switch 18, an input reactor 19 and an output capacitor 20, as well as measuring transducers: input current 21, input voltage 22, output voltage 23, output current 24, and additional converter 25 of the output voltage UVN 1. The basis of VK 18 is single-phase a bridge current rectifier composed of diodes 26, in parallel with which transistors 27 are connected, performing the function of electronic switches conducting current in the direction opposite to the direct current of the parallel connected diodes 26. Between ervym 16 UVN input terminal 1 and the first input terminal 28, the VC 18 included a series connection of the transmitter 21 and the input of the input current of the reactor 19, and the second input terminal 17 UVN 1 is connected to a second input terminal of VC 29 18 directly. The positive 30 output terminal of VK 18 is directly connected to the positive 31 output terminal of UVN, and to the negative 32 output terminal of VK 18 the negative terminal 33 of UVN 1 is connected through the output current transducer 24 of UVN 1. Its load 4 is connected to output terminals 31 and 33 of UVN , an output capacitor 20, a measuring transducer 24, and an additional measuring transducer 25 of the output voltage of the UVN 1. The outputs of the measuring transducers 22, 21, 24, and 23 of the input and output voltages and currents of the UVN 1 are connected respectively to the second, third, fourth and fifth inputs of UU 5, the output of which is connected to the control input of VK 18.

UP 2 contains a current-limiting reactor 34, first 35 and second 36 switches, as well as additional measuring transducers of input current 37 and input voltage 38 UP 2, and the first terminal of the first switch 35 is connected to the first input terminal 12 UP 2 through an additional input current measuring transducer 37 , to the second terminal of the first switch 35, the first terminals of the current-limiting reactor 34 and the second switch 36 are connected, and their second terminals are connected to the first output terminal 14 UP 2, the second input 13 and output 15 which are connected directly Agim. The outputs of the additional measuring transducers 38, 37 and 25 are connected respectively to the second, third and fourth inputs of WB 7, as well as to the second, third and fourth inputs of BOI 8, the output of which is connected to the input of the oscilloscope 9. The fifth input of BOI 8 is connected to the output of WB 7 The load of the UVN is the consumer of direct current electricity 39, which is connected through the line 40 to the consumer 39 and the switch 41, equipped with minimal protection, to the output terminals 31 and 33 of the UVN 2.

Shown in FIG. 2, the functional diagram of one phase of the control system of the three-phase bridge UVN is different from that shown in FIG. 1 is a functional diagram of a control system for a single-phase bridge UVN in that in the three-phase embodiment, the second input terminals 17 of the UVN 1 and 29 VK 18, as well as the second output terminal 15 UP 2 are missing, the second input terminal 13 UP 2, referred to in the three-phase version as zero, is connected not to the second output terminal of IN 3, but to terminal 42 of the neutral winding of the three-phase IN or to artificial zero of the electric power system, which includes this ID.

A description of the operation of the control system for a single-phase bridge UVN is given for each of the following successive stages of operation: from the 1st to the 7th, the inductance of the current-limiting reactor 19 and the capacitance of the output capacitor 20 are in steps 8 and 9, and the angle between the input voltage and input current UVN 1 - in step 10.

Stage 1. Connecting the UVN to an AC source, preliminary, uncontrolled charge of the output capacitor.

Before connecting to the source 3, the voltage U _{d of the} output capacitor 20 of the UVN 1 is zero, the first 35 and second 36 switches are open, and the consumer 39 of direct current electricity is disconnected by the switch 41, which is equipped with minimal protection. This feature of the switch 41 eliminates the short circuit of the EMF of the consumer 39 or a charged capacitor connected to its input terminals to the uncharged output capacitor 20 of the IHV 1. By the command received from the control unit 6, the first switch 35 closes and the process of uncontrolled charging of the capacitor 20 begins. for the negligible resistance of the diodes 26 in the forward direction and the absence of voltage at the terminals of the capacitor 20, the initial stage of this process is equivalent to a short circuit IN through a series connection t okoobrazhayushchego 34 and input 19 reactors: currents begin to flow through these reactors, diodes 26 and output capacitor 20. The input current UHF I _{in is} converted by an uncontrolled rectifier (composed of diodes 26) into an output current I _d , which, when the load current is equal to zero, is equal to the current charging the capacitor 20. As a result, the voltage U _{d of the} capacitor 20 begins to increase.

The inductance of the current-limiting reactor 19 and thereby the total inductance of both reactors is chosen so that the maximum input current I _in UVN 1 does not go beyond the safe values. The indicated choice, in which it is possible to neglect the active resistances of both reactors, significantly lower than their inductive resistances, is advisable to make according to the condition: the maximum of the first amplitude values of the input current I _in UVN 1 does not exceed the amplitude value of the input current UVN corresponding to the operation of the UVN in the nominal controlled mode.

To reduce the currents that occur when connecting an electrical device to an AC source, for example, when starting an asynchronous squirrel-cage motor, current-limiting resistors are usually included in the input circuit of this device. Equipped with an input reactor, an uncontrolled single-phase bridge rectifier, the output of which is closed to a large capacitor, it is better to connect to a sinusoidal voltage source through a current-limiting reactor, and not through a current-limiting resistor.

The advantage of using a current-limiting reactor to limit the input current of a single-phase uncontrolled bridge rectifier loaded on a large capacitor when connected to a single-phase sinusoidal voltage source is clearly evident when comparing the two shown in FIG. 3, static characteristics reflecting the dependence of the input current I _{in of} this rectifier on its output voltage U _d . Both characteristics are found for UVN, which has the following nominal data when operating in controlled mode:

Rated power - 10 kW, rated input voltage - 230 V, its frequency - 50 Hz, rated input current - 43.5 A, rated output voltage - U _dn 358 V, it is 10% more than the amplitude of the rated input voltage, rated output current - 27.8 A, the inductance of the input reactor is 1.24 μH, the capacity of the output capacitor is 13000 μF. The first of these characteristics, shown by a solid line, refers to the use of a current-limiting reactor with an inductance of 14.87 μH, the total inductance of the input and current-limiting reactors is 5.06 Ohms. The second characteristic, shown by the dashed line, relates to the use of a current-limiting resistor with an active resistance of 5.045 Ohms. In both cases, the input current of the UHF with short-circuited output terminals is 43.5 A, that is, the rated input current. Both characteristics coincide with the extreme points. The first of them corresponds to the short circuit mode: the output voltage is zero, and the input current is equal to the rated input current of the UVN. The second point corresponds to the idle mode: the input and output currents of the IOC are equal to zero, and its output voltage U _dmax is equal to the amplitude of the input voltage, i.e. 325.3 V. It is seen that along the entire axis of the abscissa, that is, from zero to the amplitude value of the input voltage ID 3 the first characteristic is located above the second. Consequently, at each value of the output voltage of the IHF, its input and output currents are greater when using a current-limiting reactor. In uncontrolled mode, the output current of the UHF is the current charging the capacitor 20. This current is proportional to the time derivative of the voltage U _{d of the} output capacitor 20. It follows that when using a current-limiting reactor, the capacitor 20 charges faster than would happen if a current-limiting resistor were used. It was found that the charge time of the output capacitor when using a current-limiting reactor to a voltage of 98% of the voltage U _dmax is 1.4 times less than when using a current-limiting resistor. BU 6 does not control the voltage level U _d . He compares the time t elapsed after the first switch 35 is turned on with the time Δt, which is necessary for the practical completion of the charge of the capacitor 20, for example, to a voltage of 0.98 U _dmax . At the moment when these two values are equal, BU 6 will command to turn on the second switch 36. In this case, the current-limiting reactor 34 will be shorted and only the input reactor 19 will remain in the input circuit of the UVN 1 with the value of the inductance L. UVN is ready for operation in a controlled mode. The time Δt is easiest to find by computer simulation of the process of uncontrolled charge of the capacitor 20 UVN 1.

The operation of the control system of the IHV in the controlled mode of IED 1 will be considered only for the case when the angle ϕ _{1 of the} shift of the input current of the IOC from its input sinusoidal voltage is 0. The values of this angle and the nominal output voltage of the IOC U _dn are set by BU 6 to the inputs of UU5. The voltage IN is usually maintained with an accuracy of 2.5%. Therefore, the amplitude value of the voltage IN even with its maximum possible deviation from its nominal value, will be less than U _dn , which is 1.1 times higher than the amplitude of the nominal voltage IN, which excludes the transition of the IHV to the uncontrolled charge of the output capacitor 20. The operation of the IHC is possible only in controlled mode.

Stage 2. Rectifier mode of operation of the IHF at positive values of the input voltage

The start of operation is compatible with the point in time when, when the I / O operation is in the rectifier mode, the angle θ, which is the argument of the sinusoid of the input voltage of the I / O 1, is 0.

. Входной ток i₁, имеющий положительное направление (он входит в первый выходной зажим 16 УВН 1), как и входное напряжение УВН, нарастает в течение всего времени t₁ первого включенного состояния транзисторов V3 и V4. К концу этого времени магнитное поле входного реактора станет иметь энергию E₁=L(i₁(t₁))²/2. Это время меньше периода T_s несущей частоты. Спустя время t₁ первого включенного состояния транзисторов V3 и V4 они под действием УУ 5 выключаются. Ток индуктивности i₁ не может изменяться скачком, он при t=t₁ начинает проходить по контуру: второй выходной зажим 11 ИН 3, первый выходной зажим 10 ИН 3 входной реактор 19, VD1, положительный 30 выходной зажим ВК 18, отрицательный 32 выходной зажим ВК 18, VD2, второй выходной зажим 11 ИН 3, и начинает уменьшаться, а напряжение выходного конденсатора 20, который заряжается током индуктивности L - увеличиваться. Принятые у прототипа [Электротехника. - В 3-х книгах. Книга II. Электрические машины. Промышленная электроника. Теория автоматического управления / Под ред. П.А. Бутырина, Р.Х. Гафиятуллина, А.Л. Шестакова. - Челябинск: Изд-во ЮУрГУ, 2004. - 711 с., стр. 461, 462, рисунок 25.13, (прототип)] условные обозначения VD1 и VD2 соответствуют двум диодам: включенному между первыми входным 28 и выходным 30 зажимами ВК 18 и включенному между вторыми выходным 32 и входным 29 зажимами ВК 18. К моменту времени t=T_s энергия электрического поля конденсатора 20 увеличится на указанную выше энергию Е₁ магнитного поля входного реактора 19. При t=T_s начнется второй цикл включения и отключения транзисторов V3 и V4. Работа УВН на этом цикле отличается от рассмотренной работы УВН на первом цикле тем, что напряжение ИН не равно нулю, а больше нуля. Поэтому начальная производная тока реактора больше, чем на первом цикле. Если бы время t₂ включенного состояния указанных транзисторов было бы таким же, как и на первом цикле, то выросла бы энергия, запасенная в реакторе 19 ко времени (T_s+t₂), по сравнению с энергией Е₁, оценка которой приведена выше. Увеличится и приращение напряжения U_d выходного конденсатора 20. Такие же циклы включения и отключения транзисторов V3 и V4 будут повторяться до времени, равного половине периода T₁ напряжения ИН.At this moment, the input voltage of the UVN 1 is also equal to 0, which will be detected by the voltage measuring transducer, which transmits this information to the SU 5. When the input voltage of the UVN becomes equal to 0, control signals including transistors, which prototype [Electrical Engineering. - In 3 books. Book II. Electric cars. Industrial Electronics. Theory of Automatic Control / Ed. P.A. Butyrina, R.Kh. Gafiyatullina, A.L. Shestakova. - Chelyabinsk: Publishing house of SUSU, 2004. - 711 p., P. 461, 462, figure 25.13, (prototype)] have the legend V3 and V4. The first one is connected between the positive output terminal 30 of VK 18 and its second input terminal 29, and the second is between the first input terminal 28 of VK 18 and its negative output terminal 33. The current of the opened transistors V3 and V4 will go through the circuit: positive output terminal 30 of VK 18, V3, second output terminal 11 ID 3, first output terminal 10 ID 3, input reactor 19, V4, negative output terminal 33 VK 18, positive output terminal 30 VK 18. Since u ₁ = 0 at the moment in time, then taking into account the fact that the internal resistance of IN 3, as at the source pressure, is assumed to be zero, and the active resistance of the input reactor 19 is negligible, it turns out that the voltage of the output capacitor 20 at this moment is applied to the inductance L of the input reactor 19. The positive derivative of the input current i ₁ UHF, corresponding to the transition of this current from negative to positive values is defined by the expression

. The input current i ₁ , which has a positive direction (it enters the first output terminal 16 of the IHF 1), like the input voltage of the IHF, rises during the entire time t _{1 of the} first on state of the transistors V3 and V4. By the end of this time, the magnetic field of the reactor inlet will have an energy E ₁ = L (i ₁ (t ₁₎₎ ^2/2. This time is less than the carrier period T _s . After time t _{1 of the} first on state of the transistors V3 and V4, they are turned off by the action of UU 5. Inductance current i ₁ cannot change abruptly, it starts to go along the circuit at t = t ₁ : second output terminal 11 ID 3, first output terminal 10 ID 3 input reactor 19, VD1, positive 30 output terminal VK 18, negative 32 output terminal VK 18, VD2, the second output terminal 11 IN 3, and begins to decrease, and the voltage of the output capacitor 20, which is charged by the inductance current L, increases. Adopted from the prototype [Electrical Engineering. - In 3 books. Book II. Electric cars. Industrial Electronics. Theory of Automatic Control / Ed. P.A. Butyrina, R.Kh. Gafiyatullina, A.L. Shestakova. - Chelyabinsk: SUSU Publishing House, 2004. - 711 p., Pp. 461, 462, figure 25.13, (prototype)] the legend VD1 and VD2 correspond to two diodes: connected between the first input 28 and output 30 terminals of VK 18 and turned on between the second output 32 and input 29 clamps of VK 18. By the time t = T _{s the} energy of the electric field of the capacitor 20 will increase by the above energy E _{1 of the} magnetic field of the input reactor 19. At t = T _s the second cycle of turning on and off the transistors V3 and V4. The operation of the IOC on this cycle differs from the considered operation of the IOC on the first cycle in that the voltage IN is not equal to zero, but greater than zero. Therefore, the initial derivative of the reactor current is greater than in the first cycle. If the on time t ₂ of the indicated transistors were the same as in the first cycle, then the energy stored in the reactor 19 by the time (T _s + t ₂ ) would increase compared to the energy E ₁ estimated above . The voltage increment U _{d of the} output capacitor 20 will also increase. The same on and off cycles of transistors V3 and V4 will be repeated until a time equal to half the period T _{1 of the} voltage IN.

Stage 3. Rectifier mode of operation of the IHF at negative values of the input voltage

When the operating time of the UVN in the rectifying mode becomes equal to half the period T _{1 of the} alternating voltage IN 3, the voltage u ₁ IN 3 changes its sign from positive to negative. The information received by VU5 from the measuring transducer 22 of the input voltage of the UVN 1, that the input voltage of the UVN is 0, will lead to the following result: CV 5 sends control pulses to VK 18 to open other transistors instead of V3 and V4: V1 and V2. Adopted from the prototype [Electrical Engineering. - In 3 books. Book II. Electric cars. Industrial Electronics. Theory of Automatic Control / Ed. P.A. Butyrina, R.Kh. Gafiyatullina, A.L. Shestakova. - Chelyabinsk: SUSU Publishing House, 2004. - 711 p., Pp. 461, 462, figure 25.13, (prototype)], the symbols V1 and V2 correspond to two transistors: connected between the first output 30 and input 28 terminals and connected between second input 29 and output 32 clamps VK 18.

. В течение времени t₁ первого включенного состояния транзисторов V1 и V2 входной ток УВН будет оставаться отрицательным (он выходит из первого выходного зажима 16 УВН 1), а его абсолютное значение будет возрастать. К концу этого времени магнитное поле входного реактора 19 станет иметь энергию E₁=L(i₁(T₁/2+t₁))²/2.The current of the opened transistors V1 and V2 will go through the circuit: positive 30 output terminal VK 18, V1, input reactor 19, first 10 output terminal IN 3, second 11 output terminal IN 3, V2, negative 32 output terminal VK 18, positive 30 output terminal VK 18. This current is determined by the voltage difference u ₁ and U _dn . Since at the moment in time u ₁ = 0, then, taking into account the fact that the internal resistance of the IN source, like that of the voltage source, is assumed to be zero, and the active resistance of the input reactor 19 is negligible, it turns out that the voltage of the output capacitor 20 at this moment applied to the inductance L of the input reactor 19. The negative derivative of the input current i _{1 of the} I _/ O voltage, corresponding to the transition of this current from positive to negative values, as with the input voltage of the I / O voltage, is determined by the expression

. During the time t _{1 of the} first on state of transistors V1 and V2, the input current of the UHF will remain negative (it leaves the first output terminal 16 of the UHF 1), and its absolute value will increase. By the end of this time, the magnetic field of the input reactor 19 will have an energy E ₁ = L (i ₁ (T _1/2 + t ₁₎₎ ^2/2.

After time t _{1 of the} first on state V3 and V4, they are turned off under the action of UU 5. Inductance current i ₁ cannot change abruptly, it starts to go along the circuit at t = T _1/2 + t ₁ : second output terminal 11 ID 3, first output terminal 10 ID 3, input reactor 19, VD1, positive 30 output terminal VK 18 negative 32 output terminal VK 18, VD2, the second output terminal 11 ID 3, and begins to decrease, and the voltage of the output capacitor 20, which is charged by the inductance current L, increases. Adopted from the prototype [Electrical Engineering. - In 3 books. Book II. Electric cars. Industrial Electronics. Theory of Automatic Control / Ed. P.A. Butyrina, R.Kh. Gafiyatullina, A.L. Shestakova. - Chelyabinsk: SUSU Publishing House, 2004. - 711 p., Pp. 461, 462, figure 25.13, (prototype)] the legend VD1 and VD2 correspond to two diodes: connected between the first input 28 and output 30 terminals of VK 18 and turned on between the second output 32 and input 29 terminals VK 18. By the time t = T _1/2 + T _{s the} energy of the electric field of the capacitor 20 will increase by the above energy E _{1 of the} magnetic field of the input reactor 19.

1. At t = T _1/2 + T _s , the second cycle of turning on and off the transistors V1 and V2 will begin. The operation of the IOC on this cycle differs from the considered operation of the IOC on the first cycle in that the voltage of IN 3 is not equal to zero, but less than zero. Therefore, the absolute value of the derivative of the reactor current at t> T _1/2 + T _{s is} greater than in the first cycle. If the on-time t ₂ of these transistors were the same as in the first cycle, then the energy stored in the reactor 19 by the time (T _s + t ₂ ) would increase compared to the energy E ₁ estimated above . The voltage increment U _{d of the} output capacitor 20 will also increase. The same on and off cycles of transistors V3 and V4 will be repeated until a time equal to the period T _{1 of the} voltage IN.

Stage 4. Inverter mode of operation of the IHV at positive values of the input voltage

If the EMF of the consumer 39 of electric power becomes greater than the specified value U _{dn of the} output voltage of the UVN, then this consumer will become a source of direct current electricity. Its current will change its direction and will begin to enter the positive output terminal 32 of the UVN. Information about this event UU 5 will receive from the measuring transducer 24 of the output current of the UVN. Given this information, at the time when the angle θ, which is the argument of the sinusoid of the input voltage of the I-V, and this voltage become equal to 0, VU 5 will give a command to turn on the transistors V1 and V2. The operation of the IED will begin to take place, as shown in step 3 (The rectifying mode of operation of the IAB at negative input voltage values). But in the second and subsequent cycles of switching on and off these transistors, the following differences will take place. When they are turned on, the output voltage IN 3 is not negative, but positive. Therefore, the absolute value of the derivative of the reactor current and the voltage increment of the output capacitor 20 will become smaller than shown in stage 2. The operation of the IHV 1 in the second and subsequent cycles of turning on and off these transistors will take place, as shown in stage 2 (Rectifier mode of operation of the IHC at positive values input voltage).

Stage 5. Inverter mode of operation of the IHV at negative values of the input voltage

At the point in time when the angle θ, which is the argument of the sine wave of the input voltage of the UVN, becomes equal to π, and the output voltage of IN 3 begins to pass through the zero value, UI 5 will give a command to turn on transistors V3 and V4. The operation of the IHV 1 in the first cycle of their inclusion will take place, as shown in stage 2 (Rectifier mode of operation of the IED for positive values of the input voltage). Due to the fact that after the indicated moment the output voltage IN 3 will not be positive but negative, the absolute values of the derivative of the current of the input reactor will become less than in the first cycle. Therefore, the absolute values of this current and the voltage increment of the output capacitor 20 to the end of the on state of transistors V3 and V4 in the second and subsequent cycles of turning on and off these transistors will be less than in the first cycle.

Stage 6. Features of the input voltage form VK 18

, с которой происходит коммутация транзисторов ВК 18, в сотни и более раз превосходит частоту

ИН 3. Разность u_L между напряжениями на входе УВН u₁ и на входе ВК u_in приложена к входному реактору. Первая гармоника u_in уравновешивает основную часть напряжения ИН. Разность между ними является первой гармоникой напряжения входного реактора. Именно она и индуктивное сопротивление этого реактора определяют первую гармонику входного тока УВН.Due to the voltage U _{d of the} output capacitor, the UVN, working as a stand-alone voltage inverter using pulse-width modulation (PWM), generates a voltage at the VC input, the shape of which is a sequence of rectangular pulses with a constant amplitude equal to U _d , but with variable polarity and varying in sinusoidal law their duration. Carrier frequency

, with which the switching of transistors VK 18, hundreds or more times exceeds the frequency

ID 3. The difference u _L between the voltages at the input of the UVN u ₁ and at the input of the VC u _{in is} applied to the input reactor. The first harmonic u _in balances the main part of the voltage IN. The difference between them is the first harmonic of the input reactor voltage. It is she and the inductive reactance of this reactor that determine the first harmonic of the input current of the UVN.

. Практически весь этот ряд уравновешивается соответствующими высшими гармониками напряжения входного реактора. Токи этих гармоник практически отсутствуют, так как на этих частотах индуктивное сопротивление входного реактора в сотни и более раз превосходит его индуктивное сопротивление на частоте напряжения u_in ИН 3. Входной 19 реактор играет важную роль заградительного фильтра, исключающего вредное действие токов, порожденных входным напряжением ВК u_in, на источник переменного напряжения ИН 3 и на подключенные к нему другие, помимо УВН, потребители электроэнергии.In addition to the first harmonic, the input voltage VK u _in contains a number of higher harmonics, the first of which have frequencies close to the carrier frequency

. Almost all of this series is balanced by the corresponding higher harmonics of the input reactor voltage. The currents of these harmonics are practically absent, since at these frequencies the inductance of the input reactor is hundreds or more times greater than its inductance at the voltage frequency u _in ID 3. Input 19 reactor plays an important role as a stop filter, eliminating the harmful effects of currents generated by the input voltage of the VK u _in , to the AC voltage source IN 3 and to other, in addition to the UVN, electricity consumers connected to it.

Step 7. Work when changing the set value U _{dn of the} output voltage of the UVN

When reducing the output voltage of the UHF, it is necessary to comply with the condition that the value of U _dn exceeds the setting of the minimum protection of the switch 41. A decrease in the output voltage of the UHV can only occur when load 4 is connected to its output terminals 31 and 33, when the output capacitor 20 is discharged by a constant current consumer 39 current.

With an increase in the set point of the output voltage of the I / O voltage, it will begin to increase under the action of the UU 5, which will increase the duration of the on state of the transistors and reduce the duration of the off state.

Step 8. Setting the inductance of the current-limiting reactor 19

This procedure begins by issuing a command from the control unit 6 to the control unit 2, according to which both switches 35 and 36 will be in the off state. In addition, the operator must turn off the switch 41 of the DC power consumer 39. In this case, the voltage of the output capacitor 20 becomes equal to zero, since VK 18 is disconnected from the AC voltage source, and the capacitor 20 is not connected to the consumer's EMF 39. Then, a command is sent from the control unit 6 on UP 2, through which the switch 35 closes. The process of short-circuiting of ID 3 to the input reactor 19 will begin, as described above in stage 1 of the operation of the I / O device. Next, from the output of the BU 6 to the WB 7 and the BOI 8, commands are issued that will measure the effective value of the input current of the IOC 1 and display this value on the display of the BOI 8. There is another way to obtain this value: on the command from the BO 6 the oscillogram is displayed the input current of the UHF, and the operator, having measured the amplitude value of this current and dividing it by √2, will receive the effective value of the input current of the UHF 1. If it is greater than the nominal value of the input current of the UHF 1, the operator must reduce the thickness of the nonmagnetic gap at the core reactor 19. If, conversely, it is smaller than the nominal value UVN input current, the operator must increase the thickness of the nonmagnetic gap 19 in the reactor core.

Step 9. Setting the capacitance of the output capacitor 20

This procedure can begin in controlled both rectifier and inverter operation modes of IHF 1. It starts by issuing commands from the BU 6 to WB 7 and to BOI 8, according to which the average value of the output voltage of IOU 1 will be displayed on the BOI 8 display. Then, the command from BU 6 to BOI 8 on the BOI 8 display will display the waveform of the output voltage of the UVN 1, by which the operator will determine the amplitude of the ripple of this voltage. If this amplitude exceeds the permissible 1% of the average value of the output voltage of the UHF, then the capacity of the output capacitor 20 must be increased and, conversely, reduced if the indicated amplitude is less than 1% of the average value of this voltage, thereby achieving a reduction in the charge time of the capacitor 20 in uncontrolled and in controlled modes of its charge up to the nominal value U _{dn of the} output voltage of the UVN. The operations of connecting several uncharged capacitors in parallel, in order to obtain the desired capacitance of the capacitor bank, can be performed after turning off the switches 35, 36 and 41 and discharging through the capacitor resistor, which was connected to terminals 31 and 33 of the IHV 1 before the procedure. Some consumers of direct current electricity 39, in particular stand-alone voltage inverters, are equipped with input capacitors of large capacity. The procedure described in this step should be carried out each time after replacing a consumer of direct current electricity or replacing its input capacitor.

Step 10. Setting the angle between the input voltage and the input current of the UVN

UVNs are most often used for rectifier operation when the angle ϕ ₁ is 0, which ensures the maximum value of the power factor: cosϕ ₁ = 1. But other single-phase consumers, whose power factor is significantly lower, can get power from the same IN that supplies UVN with electricity, which worsens the overall load power factor of the IN. Such consumers include those that consume reactive current, such as welding converters or single-phase thyristor rectifiers with an active inductive load. It is possible to improve the overall power factor of the IN load if all or at least part of the reactive current needed by such consumers would produce not an ID, but an I / O. Such a possibility is realized by the IED during its operation in the rectifying mode with a negative value of the angle ϕ ₁ . At the same time, the I-V behaves as an active capacitive load. To answer the question about the possibility of such a solution, you need to know the following data: the total reactive current I _r required by such consumers, the nominal values of the voltage U _1n and current I _{1n of the} IHV, as well as the power of the DC consumer. First, the limiting value I _{1amax of the} active component of the input current of the IHF is found under two conditions: firstly, the input current of the IOC must not exceed the nominal value and, secondly, the capacitive component of the input current of the IOC is equal to the total reactive current I _r .

Claims (3)

1. The control system of a controlled voltage rectifier (RPC), which contains a single-phase bridge RCD, containing a single-phase gate switch (VK), an input reactor and an output capacitor, as well as in addition to the RPC, its control device, the output of which is connected to the control input of the VK, connected by its outputs to the inputs of the control device, the control unit and measuring transducers of input and output currents and voltages of the UVN, and the first output of the control unit is connected to the control input of the control device, the load of the UVN, the output capacitor and the measuring transducer of the output voltage of the UVN are connected between the positive and negative output terminals of the UVN, and both the first and second input terminals of the UVN are connected to the output terminals of a single-phase AC voltage source or with two phase output terminals of a three-phase AC voltage source, while the input voltage measuring transducer is connected between the first and second input terminals of the UVN, the first input terminal of the UVN is connected to the first input mu VK through a serial connection of the measuring transducer of the input current of the UVN and the input reactor, and the second input terminal of the UVN is connected directly to the second input terminal of the VK, the positive output terminal of VK is connected to the positive output terminal of the UVN directly and the negative output terminal of VK is connected to the negative output terminal of the UVN through a measuring transducer of the output current of the UVN, characterized in that a device is inserted into it for connecting the UP UVN to an alternating voltage source ka, in which the first and second input terminals are directly connected to the output terminals of a single-phase AC voltage source or to two phase output terminals of a three-phase AC voltage source, and the input terminals of the UVN are connected to the output terminals of the control unit, which contains a current-limiting circuit consisting of a current-limiting reactor and the first and a second switch, wherein the first terminal of the first switch is connected to the first input terminal of the unitary enterprise, the first terminals of the second switch are connected to the second terminal of the first switch circuit breaker and current-limiting reactor, and their second terminals are connected to the first output terminal of the unitary enterprise, the second output terminal of which is connected to its second input terminal, and the control input of the unit of output is connected to the second output of the control unit. 2. The UVN control system according to claim 1, characterized in that it additionally introduces a computing unit and an information display unit, to the control inputs of which the third and fourth outputs of the control unit are connected respectively, an additional measuring converter of the output voltage of the UVN is also introduced, and in addition designed to measure the input current and input voltage UP, additional current and voltage converters, while the input terminals of the additional measuring transducers input and output bottom of the voltage are connected respectively to the input terminals of the UP and to the output terminals of the UVN. An additional input current measuring transducer is connected with its input terminals between the first input terminal of the control unit and the first terminal of the first switch, and the output terminals of all additional measuring transducers are connected one at a time to the corresponding measuring inputs of the computing unit and the information display unit, the output of which can be connected to an oscilloscope performing function of the information storage device. 3. The control system of the I / O device according to claim 1, characterized in that in the unitary enterprise for a three-phase bridge I / O device containing one for each phase, that is, three input reactors, three measuring converters of the phase input current and three measuring converters of the phase input voltage, three current-limiting reactors, first and second circuit breakers, as well as additional measuring transducers of input currents and voltage UE, and in each phase UE between its input phase clamp connected to the phase output clamp of three a phase ID, and an output phase terminal UP connected to the phase input terminal UVN, an electrical circuit is connected consisting of an additional measuring transducer of the input current UP, the first and second switches and a current-limiting reactor, and the first input terminal of the additional measuring transducer is connected to the phase input terminal of the UP input current, the second input terminal of which is connected to the first terminal of the first switch, to the second terminal of which the first terminals of the second switch are connected current-limiting reactor, the second terminals of which are connected to the output phase terminal of the control unit, the input terminals of each of the three additional transducers measuring the phase input voltage of the control unit, are connected to the corresponding phase input terminals of the control unit and to the zero input terminal of the control unit connected to the neutral terminal of the winding of a three-phase AC voltage source or to artificial zero of the electric power system, into which this voltage source enters.

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