SU1658334A1 - Method for controlling immediate frequency converter - Google Patents

Abstract

The invention relates to power converter technology. The aim of the proposed solution is to reduce the weight and size by reducing the installed power of the elements of the switching node by introducing a natural switching mode for starting load currents. The Converter contains six valve groups 7-12 connected to the terminals 4-6 of the generator 13, as well as the switching node 20 in the form of two thyristor bridges 31-36 and 37-42, between which the switching circuit 43-46 is connected. Due to the proposed control method, the generator is discharged by reactive power, which allows, when designing, to improve its weight and size parameters. 1 hp f-ly, 8 silt O y

Description

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The invention relates to electrical engineering and can be used for a frequency-controlled electric drive with asynchronous motors, especially for autonomous electric drives, for which the mass and dimensions of the energy-converting installation containing an alternating current power supply (PI) and a direct frequency converter (NFC) should be minimal , and can be applied to the p - d of known NFC schemes, whose operation was provided only in artificial switching mode.

The purpose of the invention is to reduce the mass and dimensions of the energy-generating installation by reducing the number of separate multi-phase IP windings to one and the possibility of implementing starting modes with increased currents.

Fig. 1 is a schematic diagram of the NFC; Figures 2 to 4 are block diagrams of a control unit as an example of a possible implementation of a control method; Figures 5-8 are time diagrams for explaining the operation of the control unit and the entire NFC.

The converter has m input and p output pins, where m 3,. For example, a transducer is selected (Fig. 1), having output phase terminals (PV) 1-3 and input terminals 4-6. Each PV 1-3 is connected to input pins 4-6 with the help of the main connecting valves (OPV) included in groups 7-12 of alternating current. The input pins are connected to the source 13 -power (PI), which can be used as a stator winding of a synchronous generator.

The LDP load is an asynchronous motor 14, the phases of which A. B, C can be connected into a star or a triangle.

Neutral IP 15 serves for the purpose of monitoring the voltage at the output of the NFC and, together with other input and FV NFC, is fed to the input of the control unit 16, which also receives signals from current sensors 17-19, the primary circuits of which are connected before connecting the PV A, B , With load and connection of the switching unit 20 in the common points of the connection 21-23.

The switching unit 20 is made in the form of two rectifying bridges 24, 25. The anodic and cathodic groups 26-29 can be connected in pairs directly (Fig. 1) or through the windings of the current divider, as in the known NFC (not shown). With a direct pairing connection of the leads of groups 26-29, the bridges 24, 25 turn into stars from anti-parallel-connected valves, the outputs of the rays of which are connected to the FS 1 3 at points 21–23.

the neutral 24 of one of them is connected to the first output of the artificial switching circuit 30. Additional controlled gates 31-42 (OIL), included in the above groups 27-29 of the switching unit 20, are designed to switch the load current, which can be carried out as in Eat mode of natural commutation, as well as in ISK mode of artificial commutation using a circuit 30 consisting of at least one commutation capacitor 43, or with a choke 44. which are connected in series and can be connected to the neutral of the second star with by the power of two anti-parallel connected auxiliary controlled valves 45 and 46 (VUV) connected to the capacitor 43 at point 47, and the condenser to the choke at point 48.

FIG. 2 shows a block diagram of one of the possible embodiments of the block 16 for controlling the activation of OPV, OIL and VUV, which implements the proposed method for controlling the NFC.

Unit 16 has a driver input 49, to which a driver signal of the NFC in the form of pulses with a frequency of 12, a multiple of the LFC voltage output frequency fa is supplied, and logic node 50, which provides and removes trigger signals (VCS) for groups 7-12 OPV ( Fig. 1), as well as the generation of auxiliary signals for creating conditions for switching on the VC and OIL. In addition, the block 14 is equipped with sensors 51-56 of the state of groups 7-12 (DSG), which form signals "a (I)," to (0, respectively, from the anodic and cathodic OPV group connected to the i-th PV, if In this group, at least one conductive OPV, sensors 57-62 of the polarity of each PV relative to neutral 15 (DPN0 57, 59, 61) and relative to the neighboring PV (DPN i (i + 1) 58, 60, 62), forming signals Uio (+), Uio (-) - 57: Ui2 (+), Ui2 (-) - 58; U2o (+), U2o (-) - 59; (+), U25 (-) - 60; UM (+). 11зо (-) - 61; l) 3i (+), U3i (-) - 62. In this case Ui2 (+) U2i (-) ... U3i (+) Ui3 (-) holds.

Block 16 contains signal converters 63–67 that form the corresponding normalized signals at the output, i.e. in code O, 63 is a power source converter (PIT), the output of which is a signal D U p at f) 0, where 11f) is rectified the rated voltage PI, a U f) is the set value of the voltage PI, above which the transition to the CSI mode is possible: 64 is the voltage converter of the switching capacitor (PNK), the output of which forms the signals D1) to | UK1 Ux (3) 0 and

UK (+), UK (-) in accordance with the polarity of the voltage on the capacitor 43: Converter 65-67 signals from current sensors 17-19 (PDT) for each PV generate signals at the output h (+), li (-) depending on the polarity of the flowing current ((+) from the OPV group to the load phase) and the signal of the phase current exceeding D 0, where ф is the effective value of the phase current, IH is the nominal value of the phase current for which the switching circuit is calculated.

Excess signals from the transducers are fed to the inputs of the mode setting unit (BZR) 68 of the NFC operation.

BZR 68 has three separate outputs, signals Eats. Pdg The claim on which are formed in accordance with the following logical expressions

Her, () + D1

Pdg L U X AT X (L U x dT) or

pdg Lee xxT) ck,

Lee xD |

those. The Eat signal is generated when L Un UK 0 and the signal L I - O or L G - 1 In general, the bar above the elevation designation indicates inversion, i.e the appearance of signal 1 in the absence of these signals.

This ensures that the appropriate mode is set up in the case of the presence of the signal L only or in the absence of all the excess signals, the EC signal is generated at the output of the BZR and the NFC works in the mode of natural switching of all controlled gates.

When the Lip signal appears, but only in the absence of the D1 signal, a signal Pdg is generated to prepare for the switching mode with the simultaneous disappearance of the signal Eg.

The appearance of the D UK signal will lead to the appearance of the Claim signal — the transfer of the NFC to the artificial switching mode and the removal of the PDG signal. The Claim Signal will be retained until then. while there will be a signal L UK and there is no signal D. Exits Eat, Pdg, Claim are connected to node 69, which provides the supply of switching pulses to the control electrodes of the VUV and VUV of the switching unit 20.

To the other inputs of the node 69 are connected the outputs of the node 50, which contains the distributor 70 pulses (RI) and shapers 71-76 including signals (FSH) groups 7-12 OPV.

Pulse signal 59 is converted by RI 70 into paraphase signals.

0

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0

five

0

five

0

five

0

five

with a duration of Ta / 2, shifted between direct or inverse outputs to T2 / 3. Each of the RI 70 outputs is connected to the first input 2I of an amplifier-amplifier connected to the output of FSH 71-76. Their second input is connected to the output of the element OR 2, one of the inputs of which is the enabling input of FSH, and the other is connected to the output of the element 2, OR-NOT, whose inputs are the inhibiting inputs of FSH.

Node 50 contains shapers 77-94 of confirming signals: shapers 77-82 of signals (i,) ./ () remove ViC (CBC) of the corresponding anodic, cathodic OPV group connected to the lth PV of the NPS:

the formers 83-88 of the signals VA (I), CC (I) of the polarity of voltage (FDI) of this group relative to neutral 15 after removal from this group of the trigger signal:

Formers 89 94 signals 0а 0). Јк (I) shut off all valves of the group (ZVG) after removing the switching signal from it and changing the polarity of the voltage on the PV to which it is connected

Shapers 77 88 contain element 2И and form the output signal in the case of simultaneous presence of signals at their inputs, in accordance with the logical expressions

/ U i) Uj x M i),

 (I) ui x "to (i)

VA (I) «a (I) X U | 0 (+).

 ) “K () XU | 0 (-) where Ui, Ui are the direct and inverse signals from the 1st RI 70 output, respectively.

i (i), “k (I) signals from the output of the DSG 51 56 about the presence of conductive OPV in the anodic, cathodic group, connected to the | -m PV;

and, o (4 -) - Uio (-) - the signal from the output of the DPN0 (67, 69, 71) connected between the ith PV and the neutral about the change of the polarity of the voltage.

The first prohibitory input of FSH 71-76 is connected to the PDT output of its PV, but of opposite polarity I, () FSHa (1) and to li (-) for FSGk (1), and the second prohibitory input of FSGk () is connected to the output of PSNcO + 1), Ipa (1+ 1), respectively. Due to this, the formation of VCS at the output of FSH 71-76 is delayed by the time of the flow of current of reverse polarity through the i-th PV and is interrupted when the polarity of the voltage changes on the oppositely-charged OPV group after removing the switching signal from it, while one of the OPV of this group continues to conduct.

The ZVG shapers 89-94 contain an amplifier shaper with inputs 2I, the first input of which is connected to the corresponding output of the RI 70, and the other input to the output of element 2 OR-NOT, whose inputs are connected to the outputs of the DSG 61-66 of both groups connected to l- m PV. Therefore, the signal at the output of the ZVGa (1), ZVGkk (1) is formed only in the case of locking all OPV connected to the i-th PV, but only when the signal is removed from the direct output of all OI for ZVGa (one).

The outputs of all considered shapers of confirming signals are connected to the outputs of node 69, which contains (FIG. 4) six (by the number of OPV groups connected to PV) logical blocks of triggering pulses 95-100 for shapers (PIF), PIFA) For simultaneous start of the formers 101 -112 pulses for switching on an OIL 31–42 (PID 101-112), which is carried out through the distributor 113-118 pulses (RID) for the specified OILs.

The above ZIFA (1), ZIFK () 95-100 also start pulse shapers 119, 120 (FIV) to turn on VCS 44, 45 through the connection nodes of the switching capacitor 121-126, (PQAO). PKKk (O), which together with REED (1), RIDK (1) 113-118 and with the node 127-132 enable enable (TORD), RVDK (T), respectively, are included in each SIFA), SIFA (1) 95- 100.

PIDs 101-112 each have three separate OR inputs, the first two of which are connected to RIDAO), RIDK (0 113-118, and the third one to one of the first two outputs of the PAC (1), PAC (1) 121-126. The formation of signals at the output of RID 113-118 is carried out on a signal from the output of the high-pressure hoses 127-132, which is included in their common SIFAO), SIFCO) 95-100.

The signals qa (i), qk (l) from the output of the corresponding RVD are fed to the input of RID 113-118, which is the input to the first amplifier of the former (UV1), which has two separate outputs that are connected to the inputs of two corresponding PIDs 101- 106, including the OILs of the first bridge 24 of the switching unit 20 (FIG. 1), and is also the first input of the second amplifier element 2I (UV2) with two outputs, two inputs of which are connected to the PID inputs 102-112 (FIG. 4), including OIL of the second bridge 25 of the block 20. The second input of the RID 113-118, which is the second input of the element 2I, is connected exit Eats BZR 90.

Therefore, in the ECT mode, REED 113-118 signals are generated at all four outputs, and in all other modes (PDG and ISK) - only at the first two outputs. On each

The output of each RID 113-1 18 is the PID number 101-112, to the input of which this output is connected. Similarly, at the inputs of the PID 101-112, the numbers of the RID and GAC are indicated, to which each input is connected.

Each FIV 119-120 is a UV with three separate inputs that are connected to the outputs of the corresponding PAC.

122,124, 126 for FIV 119 and for the PAC outputs 121, 123, for FIV 120.

Each PKKaO). KKKK (1) 121-126 has four entrances and four separate exits. The inputs of the PAC to the two elements 2I. the first of which is connected to the output of the ISK BZR 68 and to

the output of the corresponding CBCa (i), CBCK (i) 77-82, and the second - to the output of Пдг БЗР 68 and to the output 3ВГа (1), ЗВГк (1) 89-94. The output of the first element 2I and the first output of the second element 2I are connected to the inputs 2IL UV with

three separate outputs, the first two of which are connected to the third inputs of the corresponding PID 101-112, including one of the OILs 31-42 in each of the bridges of the block 20. The third output of the UV, included in the PACaO) 122, 124, 126, is connected to the input of the FIV 119, and the member of the PKKK (1) 121,

123,125-to the entrance of the FIV 120.

The second output of the second element 2KPKa (0, KKKK (1) 121-126 is the fourth output on which the signal Јk (i). Јa (I) is generated. Only in the Pdg mode, it goes to the fourth PSC FS enable input (1), FSHaO) and includes the opposite group of OPV. OPV group number specified

together with the designation of the signal at the fourth output of the PAC 121-126.

Each WFD 127-132 can be performed in the same way as the WFD 127, whose functions are performed using the input

element 2I, the first input of which is connected to the output of the DPN, which is connected between the lth and (1-1) -m EF on the polarity opposite to that which this OPV group provides (in the presence of a switching signal,

those. with the accepted designations, with a change in + for RVD cathode groups and a change in - for RVD anode groups). The second input element 2I is connected to the output element 2ILI, the first input of which

connected to the output NCP 64 D11k (+) for RVDaO) and AUK (-) for RVDO). The second input of the specified element 2IL is connected to the output of the IPNaO),) (of its group), and its second input is connected to the output of the element NOT, the input

which is connected to the output of the BZR Claim 68. RVD 127-132 can be performed by other schemes, however, the signal qa (l), qk (Q at the output. RVDaO), RVDO) should be formed in case

q, (l) Uac Xy, (l) XUi (ii) (+) + + Dick (+) XSC (| -1) (+), qr (l) Xyi (l) XUi (| -i) (- ) +

+ Alk (-) XUi (l-l) (-)

Thus, in accordance with the proposed control method, in the Est and Pg modes, the signal qa (l), qk (l) is formed after the occurrence of the signals ya (1), yk (I) and the change in polarity of the voltage between the i-th and ( 1-1) -m FV on the reverse, i.e. when the voltage on the polarity of the i-th PV becomes modulo more than the voltage on (1-1) -m PV, the polarity of which does not change.

In the Search mode, the signals qa (l), qk (l) are formed after the output of the OSP 64 shows a Lee signal of the opposite polarity of the voltage on the capacitor 43 (Fig. 1), and by this time there will always be a signal DPN i (i - i) on voltage polarity reversal.

Work NFC (figure 1). controlled by the control unit 16 in accordance with the proposed control method, is illustrated by time diagrams (Fig. 5) of the voltages UA (t), L) B (t). Uc (t) - on the phases of the load (Fig. 5a, b. C), on which vertically shaded rectangles are shown including signals (HCS). which are supplied to include groups 7 12 OPV, as well as linear voltages UAo (t), UBc (t), UCA (I) - which are indicated by a dashed line in the form of discontinuous rectangles, since the linear voltage is zero when instantaneous values are equal phase voltages.

The axes show switching pulses that are fed to the control electrodes of the OILs (vertically shaded rectangles) and the conduction intervals of the OILs in the E mode, when both bridges 24, 25 are simultaneously flowing at a frequency of f2 "ft, and switching pulsations are hardly noticeable.

In this case, the shape of the linear and phase voltages at the terminals of the load 14 is similar to that when the autonomous voltage inverter operates.

Figure 6 shows the time diagrams of the voltages Uio (t), U2o (t), U3o (t) (fig.b, b, c) on the FS of the NPS between the PV and the neutral 15 PI 13, which are defined

only the mode of operation of the NFC is the opposite polarity of the operation of the reverse three-phase zero rectifier.

Voltage diagrams are given for

the case of the presence of the signal Pdg at the corresponding output of block 68, at which the NFC transitions from the natural switching mode to the artificial switching mode.

Since this involves natural switching, these diagrams can serve as an illustration of the process of natural switching of the NFC

5 receiving power from IP 13 with star-connected phases — the main distinguishing feature of the control method used, as well as the process of automatic charging the switching capacitor to a predetermined voltage without additional charging circuits of the switching capacitor to a predetermined voltage value, followed by transition to the mode of artificial commutation.

The voltage on the switching capacitor 11k (1) (Fig. 6d) and the pulses applied to the IWS 45, 46 (fig.d) for its connection to the bridge 25 of the unit 20 (Fig. 1),

0 are combined in time with the supply of switching pulses to the corresponding OPV and OIL groups (Fig. 1b) in order to ensure the flow of all the processes provided for by this control method.

5 Through time T2 / 2. After the start of charging and recharging of the switching capacitor 43 (Fig. 1), the UK voltage on it (Fig.bg) becomes higher than IR (3) and the output of the Block 68 Appears, a signal appears, putting 0 NFC operation to artificial switching

The timing diagrams for the supply of switching pulses to the OIL and VUV together with the corresponding intervals of the current through the OIL and voltage Uk (t) on the switching capacitor are shown in Fig.7. It has been shown that the transition to the Lawsuit mode can be carried out at any polarity of voltage

0H on Fig. 8 shows time diagrams of voltage Uio (t) and current e (t.) For one of the FS of the FFC with the VKS supplied to groups 7, 8, which provide all this during the operation of the NFC in the UCK mode (Fig. Ba) . Timing diagrams of inclusive pulses that are applied to the OIL and VUV (Fig. 86) determine the moments of the reloading of the switching capacitor 43 (Fig. 1) in the voltage diagram (Uk (t) (Fig. 8a). Shaded triangles in the curve

the current U (t) shows the currents that are transmitted from one phase to another via the enabled OIL. In this mode, all the half-waves of the phase voltages, as well as the voltages Uk (t) on the capacitor 43, are equal to each other, and the mode itself can be realized with both h fi and f2 fi

During start-up and at low settable frequencies, the power supply voltage of the IP 13 is very small and at the output of the ECT of the BZR block 68 a signal is generated that sets the LFC natural switching mode (Fig. 5). Since the phase current can significantly exceed the nominal value at start-up and small values of fj, two OILs in each bridge 24, 25 of the switching unit 20 are simultaneously turned on, which makes it possible for the reactive current to change the polarity of the load phase along two parallel circuits from OIL.

The switching process itself is more clearly represented in Fig. 6, where the moment of change of polarity of the voltage on the 1st PV is chosen for the moment to due to the fact that up to 3joro during the time of Aty: Ti / 12 the signal Ui was removed and wils signal Ui on the corresponding RI 70 (fig.Z), and this in turn led to the removal of the WCS from group 8 of the OPV. Since the last of the conductive OPVs of group 8 remains in a conducting state, the voltage Uio (t) changes in accordance with the change in the phase voltage of the PI 13 and at the time to changes its polarity. From this point on, a signal y is generated at the output of the PDS 83, which prohibits the formation of the WCS vn for group 11 of the OPV, therefore at the moment toi the next switching of the OPV of group 11 does not occur, but, starting from this moment, Uio (t) UsoW. which allows the inclusion of an OIL. This leads to the formation of a signal qa at the output of the high-pressure hoses 128, which is fed to the RID 114 and, if there is a signal Eta at the other input, leads to the formation of a signal immediately on all its four outputs connected to the PID inputs 101, 106, 107, 102 .four). These PIDs include an OIL 31, 36 of the first bridge 24 and OIL 37, 42 of the bridge 25 of block 20 (Fig. 1.5).

When the PDG signal is present, the ECt signal is absent and the signals are formed only at two outputs of the RID 114, which are connected to the inputs of the PID 101, 106 (Fig. 4). In this case, the OIL 31, 36 of the first bridge 24 is turned on (Fig. 1.6).

The inclusion of the indicated OILs causes the last of the OPV of Group 8 to be locked, the signals / Sv,} b to be removed and the signal v to be generated. As a result, the VKS for vn for OPV group 11 is restored and the next OPV, which has the greatest potential, is switched on.

In the presence of PDG, the signal generation Јв leads to the formation of signals at the same time on all four outputs of the Mill) 122. This leads to the filing of a short CCS at the OPV of group 7. As the fourth output of the Mill) 122 is connected to

the fourth permissive input FGGk () 71 and at the output a signal v is generated, despite the presence of the signal li (-), as well as to the supply of switching pulses to the FID 101, 111 and to FIV 119. This is in turn

leads to the connection of the switching capacitor 43 between the PV 1 and 2 with OIL 31.41 and VUV46.

If the charging current of the switching capacitor (at low voltage

The PI is less than the reactive current flowing from the PV 1 to OIL 31, 36, then OIL 36 is not prohibited, and it is possible that the OPV of Group 7 is not included. Therefore, all OIL 31, 34, 41 will spend some time together

the current until the UK voltage exceeds the rectified voltage of the PI, and the VUV 45 and OIL 41 are closed, and OIL 31 and 36 will pass the current for some time until it decreases to zero, and OIL 31 and 36 will also be closed. After this moment, the H (-) signal disappears and the FGK () 71 generates a signal P for switching on the OPV group 7.

After time T 2/6 after removing the WCS from group 8, the WCS from group is removed

c OPV.

After switching T 2/6 after switching the signals from Ui to Ui to RI 60, signals 1) C to Kz are switched and the HCS is removed from group 11 of the OPV. Due to the similar

polarization process

voltage on the FVZ occurs removal of the CCS from OPV group 10, and after the FVZ becomes more negative than the PV 2, and U32 changes the polarity to the opposite

in the manner described, the OILs 32 and 36 are turned on, and after the last OPV is locked from group 11, signals are formed for switching on groups 10 and 12, OIL 37, OUV 45, and re-OIL 36. This enables connecting the PV 3 to the PV 2 and recharging the capacitor 43 in the opposite direction direction.

The time interval At, during which the two groups connected to the common for them PV, FCC is not supplied, is determined by the total time At AA t2 + A13 + AU, where A ti is the decay time of the instantaneous value of voltage to zero, D ti Ti /12;

A t2 is the rise time of the voltage up to the instant of equal instantaneous values of the stresses D t2 Ti / 12;

At3 - switching time of the current OIL and lock OPV:

At4 is the flow time of the reactive current through the OIL, and can be defined as the decay time to zero current, the signal from the ACP to stop the current flow through the PV or the signal of the conductivity state sensor, similar to DSG 51-56, included for monitoring conduction groups 26-29 OIL block 20.

If during the charging time of a capacitor, the reactive current decreases to zero before the voltage on the capacitor reaches a predetermined value, the re-activation of the OIL will not be required, and the disappearance of the signal from the ACP 65-67 about the flow of current of opposite polarity .

If the capacitor is charged to a voltage higher than a predetermined value before the reactive current drops to zero, then the signal AUk (+) or AUic (-) appears together with the existing signal that the absolute value of the voltage is (1-1 ) MFV will lead to the re-formation of the signal qa (l), Qk (l) and the inclusion of the corresponding REED and OIL of the first bridge 24 of the block 20 (figure 1).

The appearance of the signal / peak after the next recharging of the switching capacitor 43 will switch the signals, at the outputs of BZR 68, the Claim signal will turn on and the PDg will disappear. This will lead to the fact that the PAC will start generating signals only at its first three outputs and immediately after removing the WCS with the OPV group associated with it.

This mode is shown in Fig. 6b from the moment of polarity change of the voltage on the FS 1 s + to - after the next recharging of the capacitor, as well as in Fig. 7 from the time t 9T2 / 12 3T2 / 4, after which the Lawsuit mode begins. In this mode (Fig. 8), signals are also switched at the output of the RI 70, Ui is removed, but supplied. As a result, the VB is removed and the For / G is generated, which is supplied to the PAC 122 along with the Claim signal, which results in the formation of signals on the first three outputs connected to the PID inputs 101, 111 and FIV 119. This leads to the inclusion of OIL 31, 37 and the VUV 46 and the precharged capacitor 43 is connected between the same-conductor (anode) groups 8 and 10 conducting the current. In this case, for the current-carrying OPV of group 8, the discharge current of the capacitor is blocking. Therefore, the last of the conductive OPVs of group 8 is locked, and the capacitor 43 continues to recharge with the load current of the 1st PV.

After the voltage on the capacitor exceeds a predetermined value and the signal Ac is received, a signal qa will be generated, which will turn on OIL 114, OIL 31, 36 with the help of RID 114 and thereby connect the VF

1 to PV 3 for the transfer of reactive current of the 1st PV.

Similar processes will occur when switching other OPV groups in accordance with the timing diagrams.

Fig.8.

The current curve of phase 1d (1) (Fig. 3a) vertically hatched triangles shows the current that is transmitted as reactive to the PV 3. The inclined shaded triangle in the current curve after its maximum value shows the current that is transmitted from the PV 2 when connected to FV 1 with the help of OIL. Obviously, this current reduces the instantaneous value of the current,

flowing through OPV of the corresponding group from IP 13.

The part of the reactive current of each phase of the load (Fig. 8a) from the moment of locking the last OPV of the group to the moment of switching on the OIL after the appearance of the signal A UK goes to recharge of the switching capacitor 43 to the specified excess A UK of the set value UK (S), despite some A possible change in the voltage of the power source can be kept constant over the entire possible frequency range r of the voltage at the NFC output, which leads to a decrease in the installed capacity of the switching capacitor, its mass and size.

Thus, the proposed NFC control method allows the natural switching mode to be performed by a number of NFCs that receive power from a single multiphase winding with interconnected phases and which were previously intended to operate only in the artificial switching mode, and also allows in accordance with

the proposed control method, the transition to the artificial switching mode. Solving these key management issues allows these NFCs to be used in accordance with the proposed method.

control both in the natural switching mode when starting and operating at low frequencies h & fi (f2 0.2fi), and in the artificial switching mode, at which the frequency of the output voltage does not depend on the frequency of the power source.

This, in turn, allows the use of an IP with one multiphase winding, and the PI itself is performed at the output voltage frequency at which a given IP can be performed at a given power with minimum weight and dimensions.

Reducing the number of separate multiphase windings to one allows for a reduction in the number of main connecting valves (OPV) connecting the input and output pins of the NFC. The proposed control method provides increased use of the OILs of the switching node 20 in the natural switching mode, when the inrush currents can be twice the nominal value due to the formation of two parallel circuits for transmitting reactive current from phase to load phase.

All this also provides a reduction in the installed power of the elements, the mass and dimensions of the NFC and the entire power generating unit.

Claims (2)

Claim 1. Inventory control method of a direct frequency converter (NFC) containing m input pins (V) and p output phase pins (PV) interconnected with the help of main connecting gates (OPV) with incomplete control, which from the PV side combined into anode and cathode groups, a switching unit made on additional controlled valves (OIL) with incomplete control, connected in two n-phase rectifying bridges, which are connected to the PV from the AC side, at least, they are interconnected directly or through the windings of the device for current equalization, between which an artificial switching circuit is included, consisting of at least one switching capacitor, consisting in controlling the PV currents, the voltage on the switching capacitor and generating polarity signals of these parameters and their excess of Al and Di "in the absolute value of the specified values and in the control time intervals $ У Т 2/2 - Д t for each anodic or cathodic OPV group, it is served by the general including The first signal (IQS), which translates it into an uncontrolled rectifier mode, and after changing the polarity of the voltage on the considered lth PV, several OILs are connected to connect this i-ro PV 0 to another PV in the direction conducting for the current flowing through it, characterized in that, in order to reduce the mass and size of the NFC by reducing the installed power of the switching node elements by introducing a natural switching mode at starting load currents, if it exceeds a predetermined value, it forms the signal AUn, all of the indicated excess is converted into the corresponding normalized, i.e. codes O and 1, signals Al, A ifc, A Un, and sequentially set one of the three modes of operation of the NFC when the following logical conditions are met1 the mode of operation with natural commutation (Est) with ECT () + Al preparation mode (PDG) for artificial switching mode (Claim) with Pdg AU X Al x (AUK ХАТ), Claim mode with  XAI, 5 and in the ECT mode with full The CCS from the OPV group after the end of the fy signal for this group connected to the i-th PV before changing the polarity of the voltage on it, control the moment of its polarity change relative to the neutral and from this moment remove the CCS from the conducting OPV current of opposite polarity the voltages connected to the (I) -V of the PV, control the moment of change of the voltage parameter 5 between the 1st and (I) -V of the PV, and from this moment serves the switching pulses to the corresponding OILs of the switching node connecting the PV to the conductive for reactive load current 0 | -GVOFV direction, control the time of locking the ORP in the group connected to the (I) -FV, and after reducing to zero the reactive current of the 1st PV and locking the conducting OIL in accordance with the specified order is fed to the corresponding OPV group The WCS with a duration of $ y, and these operations are also carried out in the Pdg mode, in which, additionally after locking, all OPV groups connected to the i-th PV, include OILs that connect the switching capacitor with one facing to the PV connected to each other and to (1 + 1) th FS, and to the opposite the polarity of the voltage, and in the Lawsuit mode, after removing the ACS from the next OPV group connected to the I-th PV, at the same time between the ith and (1 + 1) -m PV, having at this moment the same polarity 5 nor, using the appropriate OILs, connect a switching capacitor, which with a plate having the same polarity, connect to the 1st PV, control its recharge time to a predetermined value, and include the corresponding OIL that connect the 1st PV to (S) - FU, where is the period and fz is the voltage frequency at the converter output, A t is the time of current flow through the FW from the moment removing the CCS before its decrease to zero after changing the polarity of the voltage, n 3 are integers, and l n, and when, always I + 1 1, and at 1 1 1-1 3 2. The method according to claim 1, characterized in that, in the ECT mode, the OILs of both bridges, which are connected to the 1st and (1-1) -FV of their like power electrodes, are simultaneously turned on. "About s 51 52 H: M } 1I. . DSG 53 I 55 56 & E ; , " sh I SHShShSh-1M1-m + - nl- + and-) and ti i20 ia # and si FIG. 2 PMafJf Fig . Ar / U iv "w 5ft OH 8Ј 9 gfjf, tf tf,  L # t g % r tt WlЈ d gpf. // # /. fi .// i / g P J s t s g i o -p-nf.-z-i-mi-i-- r- r-ir-if - r-TT-im - r-i- n- U nfl gl shchishshppshsh i | nnm miumiimunm .. & F “A and% it g U l # p t J s t s g i f - r-TT-im - r-i- n- -r f h shptszshshshdtsts % Y .mf l, /  i V7 l / lhi i jl Editor B, Danko Fig 8 Compiled by G. Mycyk Tehred M. Morgentalkorrektor M, Kucher va