RU120822U1 - FULL-BRIDGE POWER SUPPLY WITH ASYMMETRIC POWER KEY CONTROL DIAGRAM WITHOUT HARDWARE PWM CONTROLLER - Google Patents

Abstract

Full-bridge power supply with an asymmetric power switch control circuit without a hardware PWM controller, containing a microcontroller unit that transmits control pulses through a galvanic isolation unit to a power switch control unit, a current and voltage level matching unit, a filter and protection against voltage surges, an input voltage rectification unit connected to an auxiliary power supply unit and a power switch unit that generates pulses to a power transformer unit connected to a rectifier and filter unit, characterized in that it contains an input current measuring unit connected to an overload protection unit, an overvoltage protection unit connected to rectifier and filter unit and generating blocking commands for the microcontroller unit.

Description

The utility model (PM) relates to the field of electrical engineering, in particular, to AC voltage to DC voltage converters, with protection against emergencies and incorrect operation, without a PWM hardware controller, has galvanic isolation with the ability to programmatically set the output voltage in a wide range.

Known intelligent power source (RF patent No. 92210, G06F 1/00 dated 02.11.2009). A well-known intelligent power source contains a voltage converter consisting of six field-effect transistors, four gate drivers of a field-effect transistor and an autotransformer, an output filter consisting of two LR circuits, a capacitor, a balancing transformer, two varistors, an RC circuit and a spark gap, an output filter consisting from an RC circuit, a diode, three smoothing reactors, two smoothing capacitors, a current sensor, a voltage sensor, two feedthrough capacitors and a resistor, a microcontroller, a receiver Serial sensor, the positive input bus, the output positive bus, a common negative bus.

Signs of an analogue that coincide with the essential features of PM are: microcontroller, serial interface transceiver, field-effect transistor gate driver, output filter, current sensor, voltage sensor.

In the well-known intelligent power source, there is no electrical isolation between the input and output circuits, as well as blocks of protection against overloads and excess voltage.

Closest to the proposed technical solution is the device "Intelligent power source" (RF patent No. 112540, Н02М 7/00, 2006), containing an input filter, a voltage converter, an output filter, a microcontroller, an interface transceiver, an input positive bus, an output positive bus, moreover, the voltage Converter contains four field-effect transistors, four gate driver of the field-effect transistor, while the four outputs of the port of the universal inputs / outputs of the microcontroller are connected to the corresponding field-effect transistor shutter drivers, the output filter contains a serial RC circuit, three smoothing chokes, two smoothing capacitors, a current sensor, a voltage sensor, two pass-through capacitors, the plates of which are connected using a resistor, while the first output of the current sensor is connected to the first input, and voltage sensor output - with the second input of the analog-to-digital converter of the microcontroller, the second output of the current sensor is connected to the first input of the voltage sensor and through the first passage capacitor - with positive m output of the power source, the output filter is enclosed in a shielding circuit that includes two feedthrough capacitors and a resistor, the microcontroller UART port is connected to the first terminals of the interface transceiver, the second terminals of which are connected to external devices (computer, power switch, control panel), JTAG port the microcontroller is connected to the JTAG interface of the workstation for tuning and debugging the microcontroller programs, the input filter contains two chokes, a balancing transformer, two varistors, excellent characterized in that the input filter additionally contains a choke and a varistor, while the phase "A" of the power supply through the first choke and the first winding of the balancing transformer is connected to the first and second varistors, the phase "B" of the power supply through the second choke and the second winding of the balancing transformer is connected with the second and third varistors, the phase "C" of the power source through the third inductor and the third winding of the balancing transformer is connected to the first and third varistors, the outputs of the input filter are connected to additional primary windings of power transformers connected by a “star” and inputs of a three-phase rectifier, which includes six diodes and a capacitor, one of the outputs of the rectifier is connected to the input positive bus, and the other to the input negative bus, the voltage converter additionally contains a parallel RL- the circuit, the primary winding of the transformer, two serial RC circuits and a varistor, while the drains of the first and second field-effect transistors are connected to the input positive bus, the source of the first the field-effect transistor is connected to the parallel RL circuit and the drain of the third field-effect transistor, the source of the second field-effect transistor is connected to the second terminal of the transformer primary winding, a serial RC circuit, and the drain of the fourth field-effect transistor, the first terminal of the transformer primary winding is connected to the parallel RL-circuit and serial RC circuit, the sources of the third and fourth field-effect transistors are connected to the input negative bus, the input positive bus is connected to the input negative bus through the second a serial RC circuit and a varistor, the output filter additionally contains a secondary winding of the transformer, two field effect transistors, two gate drivers of the field effect transistor, two diodes, a serial RC circuit and a varistor, while the secondary winding of the transformer is shunted by the first serial RC circuit, the first output is secondary the transformer windings are connected to the first smoothing inductor, the drain of the second field-effect transistor and the cathode of the second diode, the second terminal of the transformer secondary winding is connected to the second smoothing with a choke, a drain of the first field-effect transistor and the cathode of the first diode, the connection point of the first and second smoothing choke and the first smoothing capacitor through the third smoothing choke connected to the input of the current sensor, the output positive bus connected to the output negative bus through a serial RC circuit, the second smoothing a capacitor and a varistor, while the sources of the first and second field-effect transistors, the anodes of the first and second diodes are connected to the output negative bus, two outputs of the uni port The individual inputs / outputs of the microcontroller are connected to the first and second gate drivers of the field-effect transistor, the secondary windings of the power transformers are connected to additional single-phase rectifiers, each consisting of four diodes, the outputs of the single-phase rectifiers are connected to the third, fourth, and fifth inputs of the analog-to-digital converter of the microcontroller, and through diode isolation with a secondary power source of the microcontroller, the output of which is connected to the power input of the microcontroller.

Signs of an analogue that coincide with the essential features of the PM are the blocks: input filter (filter block and surge protection for PM), a rectifier (rectifier of the input voltage rectifier for PM), a secondary microcontroller power supply (auxiliary power block for PM), microcontroller ( microcontroller unit at the PM), a rectifier and an output filter (rectification and filter unit at the PM), a current sensor (unit of the output current meter at the PM), an interface transceiver (digital interface unit at the PM).

Reasons that hinder the achievement of the technical result are: lack of an overload protection unit, an overvoltage protection unit, an input current meter unit. The absence of these units in the analogue does not allow for full protection of the power source in the event of a short circuit of the output or open circuit, The MSP430F5437IPN microcontroller used in the analogue takes some time to digitize the output voltage, which does not allow tracking dynamic bursts of the output voltage, for example, during a load break. Also, the absence of an input current measuring unit and an overload protection unit does not protect input keys during short-term current overloads.

The task, which PM is aimed at, was to create a bridge power supply with an asymmetric power switch control circuit without a hardware PWM controller with protection against emergencies and incorrect operation during operation, which has galvanic isolation with the possibility of setting the output voltage in a wide range.

The technical result is achieved by the fact that the PM contains a microcontroller, a unit for matching current and voltage levels, an input current meter unit, an output current meter unit, a filter and surge protection unit, an overload protection unit, a surge protection unit.

The proposed utility model is illustrated by a drawing (Fig.), Where:

1) power key block;

2) input current meter block;

3) power transformer unit;

4) rectification unit and filters;

5) output current meter block;

6) filter and surge protection unit;

7) power key control unit;

8) input voltage rectification unit;

9) galvanic isolation unit;

10) overload protection unit;

11) overvoltage protection unit;

12) a unit for matching current and voltage levels;

13) auxiliary power unit;

14) microcontroller unit;

15) digital interface unit.

The operation of the device begins with the supply of supply voltage to the filter unit and protection against voltage surges (6). In this unit, the input voltage supplied to the module is filtered and then fed to the input voltage rectification unit (8), where the alternating voltage is converted to direct voltage and applied to the power switch unit (1) and the auxiliary power unit (13).

The auxiliary supply side (13) forms the supply voltage galvanically isolated from the input circuits for the control part: the microcontroller unit (14), and also generates an uninsulated supply voltage for the power switch control unit (7).

After the auxiliary power unit generates all the necessary voltages for the module to work, the microcontroller unit (14) is started. This block defines the basic algorithm of the entire device. After starting, the microcontroller unit interrogates the unit for matching current and voltage levels (12), the digital interface unit (15). After diagnostics and interrogation of all systems, the microcontroller unit (14) issues control pulses through the galvanic isolation unit (9) to the power switch control unit (7), which, in turn, generates the opening and closing signals to the power switch unit (1).

Next, using the power switch block (1), the input voltage is supplied by pulses to the power transformer block (3), where the input voltage is lowered and fed to the rectification and filter block (4), after which, passing through the output current meter block (5), fed to the load.

Data on the level of the output current and voltage is supplied to the block matching the current and voltage levels (12). In this block, the levels of the output current and voltage are matched to the levels necessary for the microcontroller block (14).

The input current meter block (2) is designed to measure the current flowing through power switches. The measured current is supplied to the overload protection unit (10), which compares the current level with the maximum permissible level and, if it is exceeded, blocks the control pulses generated by the microcontroller unit (14).

Overvoltage protection unit (11) monitors the output voltage and compares it with the maximum allowable. If the output voltage exceeds a predetermined threshold, then this block blocks the control pulses generated by the microcontroller block (14).

Currently, the company LLC "PIK" made one prototype of the proposed device. Tests confirmed its performance and compliance with all declared characteristics.

Claims (1)

Full-bridge power supply with an asymmetric power switch control circuit without a hardware PWM controller, containing a microcontroller unit that transmits control pulses through a galvanic isolation unit to the power switch control unit, a unit for matching current and voltage levels, a filter and surge protection unit, an input voltage rectification unit connected to the auxiliary power unit and the power switch unit, forming pulses on the power transformer unit, connected to the unit Nia and filters, characterized in that the input unit comprises a current measuring unit connected to the overload protection block from exceeding the voltage connected to the rectifier and filter unit, and forming a lock command to the microcontroller unit.