SK289145B6 - Single-branch matrix converter control - Google Patents

Abstract

The control of a single-branch matrix converter consists of a single-branch matrix converter (1) with a symmetrical power supply, a source (2) of a reference signal, a block (3) of measurement, a generator (4) of a saw, a SIM (5) and an exciter (6). The control of the single-branch matrix converter is characterized by the fact that the single-branch matrix converter creates a voltage for the load exactly according to the reference signal from the symmetrical source voltages, thereby achieving the desired behavior of the load. It is possible to smoothly change the magnitude of current and voltage, frequency and power.

Description

The field of technology

The subject of the invention is a device for controlling a single-branch matrix inverter, which is primarily intended for controlling a single-branch matrix inverter powered from a symmetrical source with a derived center. The invention belongs to the field of power electronics.

Current state of the art

Matrix inverters are inverters that allow AC appliances to be powered directly from the AC power supply system, by direct energy conversion (without the need for rectification). They are mainly used in the field of (three- and multi-phase) drives with higher outputs. They are most often fed from a three-phase network, while the converter output can have a lower or higher number of phases depending on the type of load (Antoni Arias: Notes on Matrix Converters, http://egdk.ttu.ee/files/2013/Tema_Matrix._Tallinn_May_2013.pdf). For their operation, they require the use of switches allowing to lead and control the flow of current in both directions. A separate category are single-phase matrix converters, intended for powering single-phase applications from a single-phase network (A. Zuckerberger; D. Weinstock; A. Alexandrovitz, Single-phase matrix converter, IEE Proceedings - Electric Power Applications, Volume: 144, Issue: 4, Jul 1997, pp. 235-240, ISSN 1350-2352). The disadvantage of single-phase matrix converters is the fact that when the mains voltage crosses zero, they cannot supply voltage to the load (this problem does not occur in multiphase applications), and therefore the power supplied to the load has a pulsating character. With the correct choice of output voltage frequencies, this problem can be eliminated, but in the end, the possibility of using this converter is very limited. Single-leg matrix converter (S. Kascak, R. Konarik, B. Dobrucky, M. Prazenica, M. Jarabicova: Enhanced single-leg LC matrix converter by switched capacitor and LC filter, 2017 19th International Conference on Electrical Drives and Power Electronics - EDPE , ISSN 1339-3944) represents a topologically simpler connection, but it requires a more complicated power source - a symmetrical source with a derived center. The present invention makes it possible to create an output voltage exactly corresponding to the reference voltage using a single-branch matrix converter by switching symmetrical supply voltages against the zero point.

The essence of the invention

The device for controlling a single-branch matrix converter consists of two parts.

The first part is formed by a single-branch matrix converter powered by a symmetrical power supply, while the load is connected between the output center of the power supply and the output of the single-branch matrix converter.

The second part is the control, where the required reference voltage is compared with the sawtooth pattern and, based on the measured currently available voltage from the symmetrical source, it is evaluated for switching pulses in the width pulse modulator (hereafter ŠIM). The evaluated switching pulses are amplified in the driver to the voltage and current levels required for the two-way switches of the single-branch matrix converter.

The device for controlling the single-branch matrix converter is characterized by the fact that the single-branch matrix converter creates a voltage for the load exactly according to the reference signal from the symmetrical voltages of the source. The device achieves high accuracy and dynamics while maintaining all the properties of a single-branch matrix converter.

Overview of images on drawings

In fig. 1 shows a block diagram of a device for controlling a single-branch matrix converter.

Examples of implementation of the invention

Device for controlling a single-branch matrix converter, according to fig. 1, consists of a single-branch matrix converter 1 with a symmetrical power source, the current voltages of the symmetrical source are sensed and evaluated in the measurement block 3. Based on the requested reference from the source 2 of the reference signal, the voltage from the measuring block 3 and the current value of the saw from the generator 4 of the saw, the SIM modulator 5 evaluates the switching state for the single-branch matrix converter 1 with a symmetrical power supply. This switching state is supplied in the form of pulses to the exciter 6, which adjusts its performance to the needs of the two-way switches S1 and S2 of the single-branch matrix converter 1 with a symmetrical power source.

Industrial applicability

The device for controlling a single-branch matrix converter is primarily intended for single-phase applications, but after supplementing with a capacitor, it can also be used for two-phase applications. With this device, it is possible to achieve that the voltage on the load will exactly correspond to the reference - required signal, and in addition, the control allows to smoothly change the magnitude of the current and voltage, the frequency, and thus also the power of the connected load.

List of relationship tags

- Single-branch matrix inverter with symmetrical power supply

- Reference signal source

3 - Measurement block

- Saw generator

- SIM

- Alarm clock

- Two-way switch

52 - Two-way switch

GND - Ground of the device

Claims (1)

Device for controlling a single-branch matrix converter consisting of a single-branch matrix converter (1) with a symmetrical power supply, a source (2) of a reference signal, a block (3) 5 of measurement, a generator (4) of a saw, a SIM (5), an exciter (6) and two-way switches (S1) and (S2), characterized by the fact that the measuring block (3) is connected to the symmetrical power supplies of the single-branch matrix converter (1), further the source (2) of the reference signal, the generator (4) of the saws and the output from block (3) measurements are connected by means of signal wires to SIM (5), the output of which is connected by means of signal wires to the input of the exciter (6), further by means of signal wires the output of the exciter (6) 10 is connected to the control electrodes of the two-way switches (S1 ) and (S2) of a single-branch matrix converter (1) with a symmetrical power supply.