RU2788306C1 - Transport type inverter - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: invention relates to the field of electrical engineering and is intended to control traction electric machines (synchronous and asynchronous) as part of vehicles, ships and other devices. The inverter consists of an aluminum case, an IGBT power module, a power capacitor, output current sensors, a printed circuit board of a two-layer control system, a connection block, cable glands, while the IGBT power module is attached to the main body of the inverter, which also combines the function of liquid cooling, through external fittings the coolant is supplied inside the inverter housing and cools the power IGBT module through a thermal contact, and the output buses from the IGBT module are connected to the inverter connection block through the current sensors based on the Hall effect, which serves to connect the DC input voltage and the output of the three phases of the electric motor, while the input voltage is connected via busbars to the power capacitor of the DC link and further through the terminals to the IGBT module, and the external connector of the signal interfaces is connected directly to the printed circuit board of the control system, which includes the voltage sensor of the Ud link and the system y board containing external interfaces and power drivers.

EFFECT: invention allows to control traction electric machines (synchronous and asynchronous) as part of vehicles, ships and other devices.

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Description

The invention relates to the field of electrical engineering and is intended to control traction electric machines (synchronous and asynchronous) as part of vehicles, ships, and other devices.

From the document WO 2022113732 A1, publ. 02/06/2022 an AC motor control device is known, equipped with an inverter that converts direct current into alternating current to supply alternating current to an electric motor. AC motor control device by means of sensorless control without the use of a rotor encoder. The device is designed to control a traction electric drive with a rotor position sensor or a speed sensor in the form of an encoder.

This motor control device has an inverter that converts DC to AC based on a pulse width modulation signal, and a wiring circuit connecting the inverter and the AC motor winding in the inner layer. The board is installed on the main surface of the multilayer printed circuit board in such a way as to face the wiring diagram, with the winding direction oriented in a predetermined direction, crossing the wiring diagram, connected in series and connected to a reference potential. A plurality of chip inductors forming a series circuit having a midpoint, terminating resistors connected between the midpoint of the series circuit and both ends of the series circuit, and the above-described series circuit. The rotor position of an AC motor is estimated using a differential amplification circuit in which a pair of input ends are connected to both ends and an output of the differential amplification circuit, and the inverter is evaluated according to the assumed position of the rotor. Includes a control unit that generates a pulse-width modulated signal to feed it.

From document CN113708668 A, publ. On 11/26/2021, an inverter is known that contains a U-phase inverting unit, a V-phase inverting unit, and a W-phase inverting unit, wherein the U-phase inverting unit, the V-phase inverting unit, and the W-phase inverting unit, respectively, are formed by connecting a plurality of discrete IGBT transistors connected in parallel.

From US2018337623 A1, publ. On November 22, 2018, a drive device and a method for controlling a drive device are known, which can both contain the increase in the computational load of the control unit and ensure engine controllability. The driving device according to the invention uses the following configurations for the above main purpose. The first aspect of the disclosure provides a driving device. The driving device includes a motor, an inverter configured to drive the motor by switching a plurality of switching elements, and an electronic control unit. The electronic control unit is configured to detect the electrical angle of the engine as the detected electrical angle. The electronic control unit is configured to control the inverter using pulse width modulation. The electronic control unit is configured to perform the first control at an interval of one period of the carrier wave. The first control is a d-axis and q-axis voltage command command control based on the torque command for the motor and the detected electrical angle. The electronic control unit is configured to perform second control at carrier wave half-cycle intervals. The second control is a control including control of calculating a predicted electrical angle based on the detected electrical angle. The predicted electrical angle is used to generate a pulse width modulation signal.

The closest analogue is an AC motor control device (AC), including an inverter, a controller, a synchronous pulse generating circuit, an asynchronous pulse generating circuit, a control mode switching determinant and a selector. The inverter is configured to convert direct current (DC) input power from a power supply to alternating current (AC) power by controlling a plurality of switching elements to supply AC power to an AC motor. The controller is configured to calculate the modulation rate, which is the ratio of the voltage vector amplitude to the inverter voltage, and to calculate the phase of the voltage vector. The synchronous pulse generation circuit is configured to generate a synchronous pulse signal synchronized with the electrical angle of the AC motor as a control signal for driving an inverter depending on the modulation rate, the phase of the voltage vector, and the AC electrical angle of the motor (see US 2017331410 A1, publ. 11/16/2017)

The technical problem is the inability to use an inverter to control both synchronous and asynchronous motors, as well as the need to use a top-level controller (VCU in English terminology).

The claimed solution differs from the analogues mentioned above in that a signal processor is used, which makes it possible to significantly simplify the inverter hardware and transfer many functions to the software level.

Due to this, specialized resolver processing ASICs, an auxiliary communication processor, a safety processor are eliminated, which greatly simplifies the PCB control hardware (single solution).

Analogues use complex multilayer printed circuit boards, in contrast to the only two-layer printed circuit board.

The technical result consists in the implementation of vector control.

The technical result is achieved by implementing a transport version inverter, consisting of an aluminum case, an IGBT power module, a power capacitor, output current sensors, a printed circuit board of a two-layer control system, a connection block, sealed leads, while the IGBT power module is attached to the main body of the inverter, which is also combines the function of liquid cooling through external fittings, the coolant is supplied inside the inverter housing, and with the help of a heat exchanger cools the IGBT power module through a thermal contact, and the output buses from the IGBT power module are connected through current sensors based on the Hall effect to the inverter connection block, which serves to connect input DC voltage and output of three phases of the electric motor, while the input voltage is connected through the tires to the power capacitor of the DC link and then through the terminals to the IGBT power module, and the external connector of the signal interfaces is connected It is connected directly to the printed circuit board of the control system, which includes the Ud link voltage sensor and the control system containing external interfaces and power drivers, while the electrical interface between the drivers and the control contacts of the IGBT power module is realized by spring contacts.

The connection to the current sensors of the output circuits is made by wire to the connection block of the printed circuit board of the control system.

The heat exchanger uses a parallel circuit for cooling power assemblies with flow balancing across three cooling arms.

The control system is carried out by software, consisting of a bootloader and a main program.

The output power of the inverter is 160 kW-250 kW at a voltage in the link Ud 400-850 Volts.

This design provides the following technical characteristics:

The output power of the inverter is 160 kW-250 kW (peak) at a voltage in the link Ud 400-850 Volts (depending on the type of IGBT power module used.)

Iout: 450 Amperes RMS (voltage in the link Ud up to 450 Volts)

Iout: 300 Amperes RMS (voltage in the link Ud up to 900 Volts)

Power supply for own needs: On-board network 12 Volts or 24 Volts.

Type of exchange interface: 2 channels of interface.

Interface type: speed sensors resolver or encoder.

Two galvanically isolated temperature sensors.

Precharge circuit control.

Emergency protection.

Ability to control synchronous and asynchronous electric machine.

The prototype sample was tested:

In the speed range +- 6000 rpm

In current range 400A RMS

The inverter is shown in Fig. 1 and 2, where:

1 - power capacitor

2 - printed circuit board of the control system

3 - output current sensors

4 - power cables

5 - IGBT power module

6 - connection block

7 - heat exchanger

8 - external fittings

9 - signal connector

At the same time, the claimed inverter of the transport version, in comparison with known analogues, has advantages both constructive and software.

The basic part of the inverter is the IGBT power module, which, using pulse-width modulation, generates the output voltage of the first harmonic with a given frequency and amplitude.

The presence of output current sensors allows you to organize the current feedback on the windings of the electric machine.

In the inverter device of the transport version, the liquid cooling system of the IGBT power module is used by means of a heat exchanger. The system is directly integrated into the body of the device. A parallel circuit for cooling power assemblies is used with flow balancing along three cooling arms. The scheme of organization of the liquid flow inside the cooling zone of the device is shown in Fig. 3.

The proposed transport version inverter contains a universal hardware interface for all types of electric machines in terms of rotor position and speed sensors.

To control different electric machines, only the inverter software needs to be changed.

The upper controller bypass is achieved by the inverter software.

The electrical interface between the drivers and the control contacts of the IGBT power module is implemented by spring contacts. This technology provides ease and manufacturability of the inverter assembly.

The control algorithms for electric machines use vector control with a number of functions, in particular, online linearization of the rotor position resolver throughout the entire life of the inverter, calibration during operation of the output current sensors to eliminate the aging process and other effects on the reduction of technical characteristics, algorithms are used to reduce transmission oscillations in move.

To implement vector control of a synchronous electric machine, it is necessary to know the position of the rotor at any arbitrary moment in time.

Figures below show the principles of implementing software processing of resolver signals (Fig. 4, 5).

The excitation winding receives a sinusoidal signal with a frequency of 10 kHz and an amplitude of 7 volts.

The modulated voltage of the sine and cosine windings is removed from the signal windings.

These signals are fed to the input of the ADC of the processor installed on the printed circuit board of the control system, the sine and cosine voltage envelopes are extracted, and then, using the trigonometric transformation performed by the software transformation, the rotor position angle is selected.

To increase the reliability of the angle in conditions of strong interference, a phase angle adjustment circuit is organized.

All control algorithms are implemented in software form by the central control processor (Fig. 6).

The central processor has two blocks of software (hereinafter referred to as software): the bootloader and the main program.

The bootloader provides the ability to change the main software via the CAN communication channel.

Software update is carried out by the domestic CAN adapter MARAFHON-CAN and applications under Windows.

In FIG. 7 is a diagram showing the non-linearity of the resolver angle position sensor.

In the software, in the block of the main program, a “reference” position of the corner is formed.

And the error of the real angle of the resolver is calculated. This error is entered in the correction table. This correction is added to the resolver angle and then used in the math.

All necessary signals and parameters (parameters of the gas and brake pedals, parameters of the traction battery and its limits in motor and generator mode, additional parameters of the cooling system) are transmitted to the inverter via the CAN bus.

And the vector control of the electric motor is implemented.

The signal from the output current sensors is fed to the clarke conversion module of the main program, where it is converted into a two-phase coordinate system.

And then, with the help of the transformation of the park, it is converted into a fixed coordinate system where the active current Iq is proportional to the moment and the reactive current Id is proportional to the magnetic flux.

By adjusting these components, you can control the moment and speed of the electric machine in an arbitrary direction.

The reverse park and clark conversion restores the three-phase voltage at the output terminals of the inverter.

The ability to use two inverters in the "master-slave" mode to organize a two-motor electronic differential without the use of external controllers.

To organize the master-slave mode, two inverters are used, while the bundles of inverters must be connected together via the CAN information bus.

In the service software of the inverter, designate the “master” mode for one inverter, the “slave” mode for the other inverter. The inverters will start in master-follower mode.

The use of a bunch of inverters and original control algorithms as part of the software makes it possible to implement the control schemes shown in Fig. 8.

The use of an inverter as part of a vehicle eliminates the need to use a top-level controller (VCU in English terminology).

All functions of transmission control, interrogation of the gas and brake pedals, reading the state of the high-voltage battery, and the vehicle control model are implemented in FIG. 8 - Features of all-wheel drive layout diagrams:

- traditional differential drive (a),

- combination of differential and individual electric drives (b),

- individual type of drive with sprung electric drives (c),

- individual type of drive with unsprung electric drives (d), where

10 - electric motors; 11 - gearboxes.

This feature applies to both single-engine and multi-engine solutions.

For high-quality control of output currents, a fast current control loop with a time of 50-150 μs is used.

The modes listed above have not been previously used and are not used in existing analogues.

The principle of operation of frequency regulation is based on the dependence of the speed of rotation and the moment of force on the shaft of an alternating current motor on the frequency of the supply voltage. Frequency regulators change the frequency of the voltage applied to the electric motor, thereby regulating the speed of rotation of the rotor and the moment of force.

The frequency converter is built on the basis of double conversion circuits. This technical solution has the following advantages:

The ability to change the frequency both up and down.

The output voltage is pure sinusoidal.

Absence of higher harmonics.

Smooth, high-precision regulation of the frequency of the supply voltage of the motor.

Such a frequency converter consists of three blocks:

DC link - filter. This node smooths out the current ripples from the high-voltage battery.

Inverting block. This element performs the inverse conversion of direct voltage to alternating voltage. The inductive element at the output filters the constant component, as well as high-frequency interference, the presence of which adversely affects the operation of the electric motor.

Control circuit based on microprocessor. Its main functions are to set the frequency of the output voltage and current. The frequency of the current at the output of the inverter is determined by the width or duration of the control pulses from the control circuit (width- or frequency-pulse modulation). The processor also provides communication with remote control points, automatic feedback control on the mechanical and electrical characteristics of the electrical machine connected to it, as well as other functions.

Thus, with frequency regulation, the supply voltage is first converted to DC, then inverted to AC voltage of the required frequency.

Claims (5)

1. An inverter designed to control traction electric machines as part of vehicles, consisting of an aluminum case, an IGBT power module, a power capacitor, output current sensors, a printed circuit board of a two-layer control system, a connection block, sealed leads, while the IGBT power module is attached to the main the inverter case, which also combines the function of liquid cooling, through external fittings, the coolant is supplied inside the inverter case and, using a heat exchanger, cools the IGBT power module through a thermal contact, and the output buses from the IGBT power module are connected to the inverter connection block through current sensors based on the Hall effect , which serves to connect the DC input voltage and the output of the three phases of the electric motor, while the input voltage is connected via buses to the power capacitor of the DC link and then through the terminals to the IGBT power module, and the external connector of the signal inter of the faces is connected directly to the printed circuit board of the control system, which includes the Ud link voltage sensor and the control system containing external interfaces and power drivers, while the electrical interface between the drivers and the control contacts of the IGBT power module is realized by spring contacts. 2. The inverter of the transport version according to claim 1, characterized in that the connection to the current sensors of the output circuits is made by wire to the block of the printed circuit board of the control system. 3. The inverter of the transport version according to claim 1, characterized in that the heat exchanger uses a parallel circuit for cooling power assemblies with flow balancing over three cooling arms. 4. The inverter of the transport version according to claim 1, characterized in that the control system is carried out by software, consisting of a boot loader and a main program. 5. The inverter of the transport version according to claim 1, characterized in that the output power of the inverter is 160-250 kW at a voltage in the Ud link of 400-850 V.

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