RU2671539C1 - Multi-phase emf system generator for mobile devices - Google Patents

Abstract

FIELD: electrical equipment.SUBSTANCE: invention relates to the field of electrical equipment, and is intended to generate the voltages multiphase system with a given frequency and a specified number of phases based on the use of pulsed equipment. EMF multi-phase system generator comprises: a control unit, a switching unit, a power supply unit and an output transformer. Control unit comprises: a clock pulses generator, an AND element, a counter, a comparator circuit, a register, a start button, a decoder. Switching unit consists of m×n (m is the device phases number, n is the number of time intervals on the sinusoidal function T period) of the controlled electronic keys, control pulses to which come from the control unit, and switched one with the help of voltage switches come from the power supply unit. Power supply unit consists of n/2 power sources, at that, as the power sources small-sized galvanic cells, batteries or capacitors banks with the same voltages values can be used.EFFECT: technical result consists in received from small-sized power sources DC voltage conversion into the multi-phase EMF system with a given number of phases and a given frequency.1 cl, 8 dwg, 1 tbl

Description

I. The technical field to which the invention relates.

The invention relates to the field of electrical engineering. The device is designed to generate a multiphase system of voltages of the required frequency, voltage value and number of phases.

II. State of the art

II.1 Comparison with Prior Art

The use of multiphase motors as drives of mobile devices has a number of well-known advantages in comparison with DC motors and single-phase AC motors.

The proposed device is designed to generate a multiphase EMF system with the required frequency, amplitude and the required number of phases as a result of the conversion of constant voltage power supplies into a multiphase voltage system, in shape approaching a sinusoidal one. The device can be used to power multiphase motors used as drives for mobile devices. In this case, the principle of generating a voltage that is close in shape to sinusoidal in shape is used different from other devices (for example, in inverters based on PWM controllers). It differs from the device described in [1] by the principle of selecting the amplitudes of discrete pulses, the use of small-sized identical voltage sources of the same type with the same voltage values as power sources. This allows the device to be used to power the multiphase load of mobile devices.

As a multiphase load can be considered drives of robotics devices, drives of aircraft - quadrocopters and drones, multiphase devices of special equipment, the power frequency of which differs from industrial, industrial automation devices. Small-sized single-type constant voltage sources with the same voltage values can be used as electric energy sources in a multiphase emf source - galvanic power supplies of the types R, LR, SR, CR classes D, C, AA, AAA, PP3, rechargeable or capacitor batteries.

The device can be used both in stationary and mobile systems (robotics) to power multiphase AC motors, as well as to power other multiphase consumers of electric energy.

II.2 Objective of the invention.

The aim of the invention is the development of a device for converting DC voltage obtained from the same small-sized sources of EMF - battery. capacitor or galvanic power sources, into a multiphase EMF system with a given voltage value, number of phases and a given frequency based on the use of pulsed technology to power a mobile multiphase load.

II.3. Inventive step.

The proposed device for generating a multiphase voltage system for mobile devices differs from that described in [1] in that:

- the device is powered from the same small-sized EMF sources (battery, capacitor, or galvanic power sources) with the same voltage values of each source;

- a serial connection of sources of positive polarity and a serial connection of sources of negative polarity allows you to obtain multiples of the voltage of positive and negative polarity, relative to the voltage of one source, necessary for approximating the sinusoidal voltage functions of each phase by a sequence of pulse functions;

- the voltage in each phase of the generator is formed by a set of rectangular voltage pulses of a given value and the same duration TI, repeated at a given frequency. The number of pulses per period T is n = T / TI. The voltage value of each pulse is a multiple of the voltage value of one power source;

- the number of power supplies is n / 2. Here n is the number of time intervals on the period of the sinusoidal function T, approximating the sinusoidal function;

- the number of series-connected sources of positive polarity and the number of series-connected sources of negative polarity is n / 4;

- to obtain the required voltage value of the EMF of the phases of a multiphase source, a transformer is provided at the output of the device, which allows to obtain the required voltage value;

- a switching unit has been developed that allows you to connect the required power sources at the time points required for the period to the output poles of the device. The sequence of pulses with the required amplitude values in each phase of the generator is set by the control device and the switching circuit on the controlled keys.

As controlled keys, triacs, transistor switches of the required polarity and thyristors can be used. The switching matrix can be implemented using the technology of manufacturing large integrated circuits (LSI).

III. Disclosure of the invention

III.1 Approximation of a sinusoidal function by a sequence of impulse functions

In FIG. 1 shows a segment of a sinusoidal function with an amplitude E _m in the interval 0 ... 2π. Consider the portion of this function in the interval 0 ... π / 2, which is approximated by a sequence of k impulse functions with multiple amplitude values E ₁ , 2E ₁ ... kE ₁ , where

E ₁ is the amplitude value of the first pulse, E ₂ = 2E ₁ is the amplitude value of the second pulse, E _k = kE ₁ is the amplitude value of the pulse with number k. Let the duration of each pulse TI be the same for all pulses and equal to

Establishment of the dependence of the amplitude of the sinusoid and the amplitude of the first pulse based on the equality of energies

We require that the area limited by the sinusoidal function in the interval 0 ... π / 2 and the horizontal axis be equal in the same interval to the area equal to the sum of the areas of the impulse functions

Integral

From relations (2) and (3) we find the expression for the amplitude value of the first pulse:

, для k=4 (n=16) получим

, для k=6 (n=24) Е1=4/7π~0.181For E _m = 1 and k = 3 (n = 12) we obtain

, for k = 4 (n = 16) we obtain

, for k = 6 (n = 24) E1 = 4 / 7π ~ 0.181

Establishment of pulse amplitude values for the case n = 12 and m = 3

Table 1 contains the values of the pulse amplitudes for the three phases - Phase 1, Phase 2, Phase 3, which approximate the sinusoidal voltages of the first, second and third phases of the three-phase system. The first three pulses approximating the sinusoidal voltage of the first phase in the interval 0-T / 4 are shown in the figure of FIG. 1. It is accepted that the period of the sinusoidal function T is divided into 12 time intervals 1 ... 12.

The voltage values E ₁ , E ₂ , E ₃ are shown in the figure of FIG. one.

III.2. Device block diagram

The block diagram of the device is shown in the figure of FIG. 2.

In the figure of FIG. 2 shows the following device blocks:

1. The control unit. Provides a cyclic, with a given period T, alternate supply of control pulses that control the opening of electronic keys located in the switching unit;

2. The switching unit provides connection to the output terminals of the switching unit of the sources generated by the power supply.

3. The power supply generates constant voltage of a given value. The voltage of the sources are connected by switches located in the switching unit to the output terminals of the switching unit. Distinctive for the proposed device is that voltages of positive and negative polarity are formed as a result of a series connection of the same voltage sources. As power sources can be taken galvanic batteries, rechargeable and capacitor banks, etc.

4. Output transformer. A multiphase output transformer provides the required voltage at the output of the device.

In the figure of FIG. 3 shows a structural diagram of the device with an indication of the external poles of the blocks, with which the blocks are connected and controlled, and the numbering of the blocks is shown in accordance with the general circuit diagram:

- 14 - control unit;

15 - switching unit;

16 - power supply;

17 - output transformer.

In the figure of FIG. 3 shows the poles with which the blocks interact and the poles 6 and 13, with which the device is controlled. The pole numbers are indicated in accordance with the general circuit diagram of the device. The signal for starting the device is entered using pole 6. The number of time intervals n, into which the period of the sinusoidal function T is divided, is entered using pole 13. Using the poles 8 ₁ ... 8 _n, the control unit and the switching unit are connected using the poles 11 ₁ ... 11 _{n / 2} the power supply is connected to the switching unit, using the poles 10 ₁ ... 10 _m the switching unit and the output transformer are connected, the poles 12 ₁ ... 12 _m are output, the load is connected to them.

III.3 Control unit

The control unit 14 is designed to generate control pulses as a result of creating a sequence of rectangular pulses of a given duration TI and supplying these signals to the control electrodes of the controlled keys 9 located in the switching unit. The block forms a pulse sequence cyclic with a period T. The value of T is equal to the period of the sinusoidal function. The number of pulses per period T is n, the duration of one pulse TI. The values of n and TI are selected based on considerations of ensuring the required error of approximation of the sinusoidal function by a sequence of rectangular impulse functions and the cost of implementing the device. With an increase in n and a decrease in TI, the error decreases and the cost increases.

In the figure of FIG. Figure 4 shows the values of control pulses for two time instants - the fourth and fifth pulses in a row within the same period T. In Fig. 4a shows the fourth pulse. In the time interval 3TI≤t≤4TI, the value of the control pulse is 1, and for the remaining time intervals, the value of the control pulse is 0. In Fig. 4b shows the fifth fifth pulse following the fourth, acting on a time interval of 4TI≤t≤5TI. In this time interval, the value of the control pulse is 1, and for the remaining time intervals, within the period T, it is 0. In these expressions, TI is the value of the time interval in which the pulse acts. The relation T = nTI is valid, where n is the number of time intervals in one period T. For the sinusoidal function shown in the figure of FIG. 1 the number of time slots is 12.

Using electronic keys located in the switching unit, the EMF sources generated by the power supply are connected at time points specified by the control unit in accordance with the specified algorithm to the output poles of the switching unit. Switching is carried out in the open state of the key. The duration of the open state of each key is equal to TI. The number k of discrete EMF values for specific values of n = 12 and the number of phases m = 3 are shown in table 1.

The schematic diagram of the control unit is shown in the figure of FIG. 5.

The block is implemented on elements 1-7. It contains a clock pulse generator (GTI) 1, a logic element AND 2, a counter 3 of the number of pulses on the period T of the periodic function, a comparison circuit 4, register 5, a decoder 7 with the number of outputs equal to n - the number of pulse functions on the period T. Starting up the device is supplied by a signal at input 6. At input 13, a code is written for the number of time intervals n.

The output of the GTI 1 is connected to the first input of the And 2 element, the second input of which is connected to the first input 6 of the device, and the output is connected to the first input of the counter 3, the output of which is connected to the input of the decoder 7 and to the first input of the comparison circuit 4, the second input of which is connected to the output of the register 5, and the output to the second input of the counter 3, the input of the register 5 is connected to the input 13 of the device, the outputs of the decoder 7 are connected to the inputs 8 ₁ ... 8 _n , through which the control unit is connected to the switching unit.

III.4 Switching unit

Using the switching unit 15, the voltage sources coming from the power supply are connected at appropriate time intervals

(k-1) TI≤t≤kTI, k = 1, 2, ... n

to the output poles of block 10 ₁ ... 10 _m . In the written expression, TI is the duration of the time interval of one voltage pulse, n is the number of time intervals in the period T, m is the number of phases of the generator. Switching is carried out using controlled electronic keys. The pulses controlling the open state of each electronic key are received from the control unit through the poles 8 ₁ ... 8 _n . The first pulse from the control unit enters the switching unit through the pole 8 ₁ , the second pulse through the pole 8 ₂ , etc.

Schematic diagram of the switching unit for a three-phase source m = 3 for the case when the number of time intervals n in the period T is 12 is shown in the figure of FIG. 6. In the circuit diagram, the input poles from which the control pulses for opening the electronic keys are supplied are the poles 8 ₁ ... 8 ₁₂ . Through the poles 11 ₁ ..11 ₆ voltage sources E ₁ ... E _{6 are} connected to the switching unit. The value of E ₁ is determined by the voltage of one power source, E ₁ = E, E ₂ = 2E ₁ (r = 2), E ₃ = 3E ₁ (r = 3), E ₄ = -E ₁ (r = 4), E ₅ = -E ₂ (r = 5), E ₆ = -E ₃ (r = 6). Switching is carried out using controlled electronic keys. The circuit diagram shows the keys 9p, r, s, where p is the number of the time interval from 1 to 12, r is the number of the power source, s is the phase number from 1 to m. The output are poles 10 ₁ for the voltage of the first phase, 10 ₂ for the voltage of the second phase, 10 ₃ for the voltage of the third phase.

III.5 Power Supply

The power supply 16 is designed to power a generator of a multiphase EMF system using small-sized single-type constant voltage sources with the same voltage values. These can be galvanic power supplies of types R, LR, SR, CR of classes D, C, AA, AAA, PP3, rechargeable or capacitor batteries with the same voltage of each element. In the figure of FIG. 7 shows a schematic diagram of a power supply for n = 12? M = 3. The power supply through the poles 11 ₁ , 11 ₂ , 11 ₃ , 11 ₄ , 11 ₅ , 11 _{6 is} connected to the switching unit. Power supplies 18 ₁ ... 18 _{n / 4 of} positive polarity are connected to each other in series. For n = 12, these are sources 18 ₁ , 18 ₂ , 18 ₃ . Sources of negative polarity 18 _{n / 4 + 1} ... 18 _{n / 2 are} connected in series. For n = 12, these are sources 18 ₄ , 18 ₅ , 18 ₆ . By pole January ₁₁ connects a power source with voltage E ₁ = E, the pole February ₁₁ are connected two series connected source so that their voltage is E ₂ = 2E _1, the pole on March _11, are connected three series connected source to each source voltage E ₁ , their total voltage is E ₃ = 3E ₁ . By pole April ₁₁ connects the power supply with a voltage of E = -E _4, the pole on May ₁₁ connect two series connected source with a voltage of each source - E, the total voltage E ₅ = 2E _1, the pole ₁₁ June connected three series-connected source with the voltage of each - E, their total voltage is E ₆ = -3E. This allows one to obtain voltages that are multiples of the voltage of one source E. The sequence of sources with these voltage values allows us to approximate the sinusoidal phase voltages. Table 1 contains the voltage values of pulsed sources for the number of time intervals n = 12 and the number of phases m = 3.

III.6 Transformer

A transformer 17 is used to bring the output voltage levels to the required values. M single-phase transformers or one multi-phase transformer can be used. In the figure of FIG. Figure 8 shows two possible implementation schemes of an output three-phase transformer. In the figure of FIG. 8a shows a three-phase transformer implemented using three single-phase transformers. In the figure of FIG. 8b shows one three-phase transformer, three pairs of input and output coils of the transformer are located on the three rods of the magnetic circuit. These can be standard transformers, the parameters of which are close to those required, or specially designed transformers. The parameters of the transformer (transformation coefficient, efficiency, input and output voltage values) are set in each case based on the technical characteristics of the device. With poles 10 ₁ ... 10 _{m the} transformer is connected to the same poles of the switching unit, the poles 12 ₁ ... 12 _m are the output poles of the device. Using these poles, the alternating voltage of the phases of the transformer is removed. The load of the multiphase emf source is connected to them.

IV. Brief Description of the Drawings

FIG. 1 Approximation of a sinusoidal function by a sequence of impulse functions

FIG. 2 Block diagram of the device

FIG. 3 Block diagram showing the external poles

FIG. 4 Charts of control pulses

FIG. 5 Schematic diagram of the control unit

FIG. 6 Schematic diagram of the switching unit for a three-phase source m = 3, n = 12

FIG. 7 Schematic diagram of the power supply for n = 12

FIG. 8 Schematic diagram of the output transformer

V. The implementation of the invention

Description of the operation of the device. In the initial state, a code of the number of time intervals n is recorded on the register 5 at the input 13. The period of the sinusoidal function T is divided into this number of intervals when the sinusoidal function is approximated by a sequence of impulse functions. On the counter 3, a zero code is stored (the reset input to zero on the counter 3 in Fig. 5 is not shown). The operation of the device begins after a start signal is supplied at input 6 of logic element And 2. After a start signal is supplied, pulses from the output of the clock pulse generator 1 through the open element And 2 begin to flow to the input of counter 3. The code from the output of counter 3 goes to the input of decoder 7. On the output of the decoder appears a single signal only at one of its n outputs. A single signal at the i-th (i = 1 ... n) output of the decoder 7 is fed to the input of the switching unit through one of the poles 8 _i , which is connected to the control electrodes of the controlled keys 9p, r, s, where p is the number of the time interval from 1 to 12, r is the number of the power source, s is the phase number from 1 to m. The inputs of the controlled keys are connected by the poles 11 _i , i = 1 ... n / 2, to the voltage sources E ₁ ... E _{n / 2} , and the outputs of the keys 9p, r, s 12 _{i, j, p} to the output poles of the switching unit 10 ₁ ... 10 _m . In each time interval, only one constant voltage source from the set E ₁ ... E _{n / 2 is} connected to each output pole of the switching unit 10 ₁ ... 10 _m . The voltage values of the sources are equal to E ₁ = E, E ₂ = 2E, E ₃ = 3E, E ₄ = -E, E ₅ = -E ₂ = -2E, E ₆ = -E ₃ = -3E. In the circuit diagram of the switching unit, the drawing of FIG. Figure 6 shows the switching for a three-phase emf source when the number of time slots on period T is n = 12. According to the table. 1, in the first time interval, the EMF source E ₁ = E is connected to the pole 10 ₁ (phase 1), the EMF source E ₂ = 2Е is connected to the 10 ₂ pole (second phase), the E ₆ source is connected to the 10 ₃ pole (third phase) = -E3 = -3E. For other intervals from 2 to 12, switching is defined similarly. To obtain voltages E ₂ and E ₃ , a series-connected connection of sources of the same magnitude voltage is used with voltage E. This is shown in the figure of FIG. 7. The voltage E ₄ is removed from the EMF source with the voltage value E when it is inverted, i.e. E ₄ = -E. Stresses E ₅ and E ₆ are obtained as a result of a series connection of inverted sources with voltage E. As a result, E ₄ = -E, E ₅ = -2E, E ₆ = -3E. This is shown in the figure of FIG. 7.

Connection of power supplies 18 ₁ ... 18 _{n / 2} with voltages E ₁ ... E _{n / 2} to the output poles of the switching unit 10 ₁ ... 10 _{m is} carried out using controlled electronic switches. The signals that control at the time moment TI = T / n the open state of the key are received from the output of the decoder of the control unit through the poles 8 ₁ ... 8 _n . The control unit sets the sequence of control pulses. The control pulse from the pulse shaper 8 _j , j = 1 ... n is followed by the control pulse from the pulse shaper 8 _{j + 1} , until j + 1 becomes equal to n. After the termination of the pulse from the output 8 _{n, the} pulse 8 _{1 is} turned _on . In this case, the current value of the counter of the number of pulses 3 will coincide with the number n set with input 13, the counter is reset and the process is repeated.

The phase voltages removed from the poles of 10 ₁ ... 10 _m , are fed to the input of the multiphase transformer. A multiphase transformer can be made in the form of m single-phase transformers, the figure of FIG. 8a, or in the form of a single multiphase transformer, the primary and secondary phase coils of which are located on m rods of the multiphase transformer, the figure of FIG. 8b. Voltages from the secondary (output) coils of the transformer through the poles 12 ₁ ... 12 _m are supplied to the multiphase load.

VI. Literature

1. Patent No. 2016127384, IPC Н05В 1/00, 2017. L. Gavrilov EMF multiphase generator

Claims (1)

The generator of the multiphase EMF system for mobile devices contains a control unit 14, consisting of a clock pulse generator (GTI) 1, element 2, counter 3, comparison circuit 4, register 5, start button 6, decoder 7, device input 13, GTI output 1 connected to the first input of the And 2 element, the start button of the device 6 is connected to the second input of the And 2 element, the output of the And 2 element is connected to the first input of the counter 3, the output of which is connected to the input of the decoder 7 and to the first input of the comparison circuit 4, the output of the comparison circuit 4 connected to the second in by the counter 3, the register 5 is connected to the second input of the comparison circuit 4, by the input 13 of which the number of time intervals n on the period T is entered, the i-th output (i = 1, ..., n) of the decoder 7 is connected to the i-th input 8i ( i = 1, ..., n) of the switching unit 15, the poles 8 ₁ ... 8 _{n are} connected to the control electrodes of the controlled keys located in the switching unit 15, consisting of m × n (m is the number of phases of the device, n is the number of time intervals for the period sinusoidal function T) of the controlled electronic keys 9 p, r, s (where p is the number of the time interval from 1 to n, r is the source number nick power from 1 to n / 2, s - phase number from 1 to m) control pulses which are supplied from the control unit by means of the poles 8 ₁ ... 8 _n, the switched received from the power supply using the voltage keys 16 through poles ₁₁ January ... 11 _{n / 2} and when the key is open, they are transferred to the poles 10 ₁ ... 10 _m , which are the output for the switching unit, the power supply 16, consisting of n / 2 power sources, with n / 4 sources 18 ₁ ... 18 _{n / 4} s positive voltage values are connected in series and n / 4 sources with negative voltage values 18 _{n / 4 + 1} ... 18 _{n / 2 are} connected in series, these groups of elements are connected together in series and using the poles 11 ₁ ... 11 _{n / 2 are} connected to the switching unit, the output transformer 17, containing m primary coils located on the ferromagnetic magnetic circuit, which are connected by poles 10 ₁ ... 10 _m to the switching unit, and m secondary coils, which are connected by poles 12 ₁ ... 12 _m different: the principle of constructing a sequence of impulse functions based on the equality of the areas in coordinates et (voltage - time) represented by a sine function and a sequence of pulse functions with multiple values of amplitude relative to the amplitude of the first pulse, which is equivalent to their energies, as power sources 18 ₁ ... 18 _{n / 2} small-sized electrochemical cells may be used, accumulator or capacitor batteries from the same values of the voltages of the elements, the serial connection of elements 18 ₁ ... 18 _{n / 4 of} positive polarity and elements of 18 _{n / 4 + 1} ... 18 _{n / 2 of} negative polarity allows you to obtain with values that are multiple with respect to the voltage E of one element, which makes it possible to implement the stated principle of approximating the sinusoidal functions of phase voltages by sequences of pulse functions, using an output multiphase transformer or a combination of m single-phase transformers in block 17 allows you to obtain a multiphase voltage system with the required value of the supply voltage of the multiphase load .

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