RU2781945C1 - Diesel generator starter - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: invention relates to the field of electrical engineering and can be used to start a vehicle diesel generator. The claimed technical result is achieved by replacing a capacitor energy storage device based on supercapacitors, the weight and size parameters of which are commensurate with a battery, a voltage converter. The device is equipped with a step-up/step-down voltage converter connected between the positive and negative inputs/outputs of the three-phase voltage inverter and the input of the excitation current regulator and consisting of N voltage cells connected in parallel, each of which contains two transistors connected in series, shunted by reverse diodes and to the connection points of which a choke and an input current sensor connected in series are connected, which form the input/output of the step-up/step-down voltage converter. In this case, information signals from the input current sensors, the excitation current sensor, the first and second voltage sensors are fed to the inputs of the control system, which generates control signals for the excitation current regulator, step-up/step-down voltage converter and three-phase voltage inverter.

EFFECT: reduction in weight and size indicators.

1 cl, 1 dwg

Description

The invention relates to the field of electrical engineering and can be used to start a vehicle diesel generator.

A diesel locomotive start-up system is known, containing a battery, a device for disconnecting the battery from the on-board network of a diesel locomotive, a traction generator, standard starting contactors with closing contacts through which voltage is supplied to the traction generator during startup, a pulse capacitor, in the charge circuit of which a charge contactor and resistor. The capacitor is connected in parallel to the traction generator through a diode, and a charging relay is connected in parallel to it, which provides a two-stage diesel start system from a pre-charged pulse capacitor, and then from a battery (RU, patent No. 94522 U1, IPC B60L 11/06, F02N 11 / 08, published on May 27, 2010).

A disadvantage of the known start system is that it is possible to start a diesel engine only from a fully charged battery using a starter-generator.

A known vehicle power supply system, comprising a battery and an energy storage device, a power supply system control and monitoring module, a voltage conversion module, a power switching module for switching DC power circuits, a charger designed to recharge the battery and an energy storage device made in the form of an electrochemical capacitor (RU, patent No. 2520180, IPC F02N 11/08, publ. 20.06. 2014).

A disadvantage of the known vehicle power supply system is the use of an auxiliary power unit to start a diesel generator, which leads to an increase in weight and size.

A known inverter start system for a diesel generator, taken as a prototype, which includes a battery, a storage-boost converter containing a DC boost converter and a capacitor energy storage based on supercapacitors, a starting inverter and a power module for powering the excitation winding of a synchronous machine (N V. Anishchenko, I. O. Tukalov, G. I. Yarovoy, R. V. Kanunnikov, Zh. "Electrical and computer systems" No. 15 (91), 2014, pp. 212-214).

The disadvantage of the known inverter start system of a diesel generator is that the capacitor energy storage device based on supercapacitors has large weight and size parameters.

The technical result of the invention is a reduction in weight and size due to the exclusion of a capacitor energy storage from the diesel generator starter and the use of a step-up / step-down voltage converter.

The specified technical result is achieved by the fact that the diesel generator starter, including a battery connected through a contactor to the first filter tank, to the first voltage sensor and to the excitation current regulator, consisting of a transistor shunted by a reverse diode and connected in series with the diode, diesel- a generator set containing a synchronous generator with an excitation winding and a diesel engine, a three-phase voltage inverter, a control system, while the output of the excitation current regulator through the excitation current sensor is connected to the excitation winding of the synchronous generator, the power inputs of which are connected to the outputs/inputs of a three-phase voltage inverter containing three identical phase cells, each of which contains two transistors connected in series, shunted by freewheeling diodes, the connection points of which are the corresponding phase outputs / inputs of a three-phase voltage inverter, and the parallel connected phase cells ki, respectively, form the positive and negative inputs/outputs of the three-phase voltage inverter, which are shunted by the second filtering capacitance and the second voltage sensor, the device is also equipped with a step-up / step-down voltage converter connected between the positive and negative inputs/outputs of the three-phase voltage inverter and the input of the excitation current regulator and consisting of N parallel-connected voltage cells, each of which contains two series-connected transistors, shunted by reverse diodes and to the connection points of which a series-connected inductor and an input current sensor are connected, which form the input/output of a step-up/step-down voltage converter, while information signals from the input current sensors, excitation current sensor, first and second voltage sensors are fed to the inputs of the control system, which generates control signals for the excitation current regulator, step-up / step-down converter voltage and a three-phase voltage inverter.

The figure shows a block diagram of the device for starting a diesel generator.

The device for starting a diesel generator contains a battery 1 connected through a contactor 2 to the first filter tank 3, to the first voltage sensor 4 and to the excitation current regulator 5, a diesel generator set 6 containing a synchronous generator 6.1 with an excitation winding 6.1.1 and diesel 6.2, three-phase voltage inverter 7, control system 8. The excitation current regulator 5 consists of a transistor 5.1, shunted by a reverse diode 5.2 and connected in series with the diode 5.3 and the output through the excitation current sensor 9 connected to the excitation winding 6.1.1 of the synchronous generator 6.1, power inputs A, B, C of which are connected to the outputs/inputs of a three-phase voltage inverter 7 containing three identical phase cells 7.1, ..., 7.3, each of which contains two series-connected transistors 7.1.1 and 7.1.2, ..., 7.3.1 and 7.3.2, shunted by freewheeling diodes 7.1.3 and 7.1.4, ..., 7.3.3 and 7.3.4, the connection points of which are the corresponding phase outputs mi/inputs of the three-phase voltage inverter 7, and the parallel-connected phase cells 7.1, ..., 7.3, respectively, form the positive and negative inputs/outputs of the three-phase voltage inverter 7, which are shunted by the second filter capacitance 10 and the second voltage sensor 11. The device is also equipped with a step-up / step-down voltage converter 12 connected between the positive and negative inputs / outputs of the three-phase voltage inverter 7 and the input of the excitation current regulator 5 and consisting of N parallel-connected voltage cells 12.1, ..., 12.N, each of which contains two in series connected transistors 12.1.1 and 12.1.2, ..., 12.N.1 and 12.N.2, shunted by reverse diodes 12.1.3 and 12.1.4, ..., 12.N.3 and 12.N.4, to the connection points of which are connected in series chokes 12.1.5, ..., 12.N.5 and input current sensors 12.1.6, ..., 12.N.6, which form the inputs / outputs of the step-up / step-down converter 12 voltage, while information signals from the input sensors 12.1.6, ... 12.N.6 current, excitation current sensor 9, the first 4 and second 11 voltage sensors are fed to the inputs of the control system 8, which generates control signals for the excitation current regulator 5, step-up / step-down converter 12 voltage and tr ex-phase inverter 7 voltage.

Transistors 7.1.1 and 7.1.2, ..., 7.3.1 and 7.3.2, shunted by reverse diodes 7.1.3 and 7.1.4, ..., 7.3.3 and 7.3.4, of a three-phase voltage inverter 7 and transistors 12.1.1 and 12.1.2, ..., 12.N.1 and 12.N.2, shunted by reverse diodes 12.1.3 and 12.1.4, ..., 12.N.3 and 12.N.4 of the step-up / step-down converter 12 voltage are IGBT - modules. The first and second filter capacitances 3 and 10 are designed to smooth out voltage ripples generated by the boost/buck converter 12. Voltage cells 12.1, ..., 12.N operate with a phase shift of 360°/N to reduce the ripple current consumed from the battery 1 in the start mode of the diesel generator set 6 and reduce the excitation current ripple of the synchronous generator 6.1 when it is operating in regular mode. The number of voltage cells 12.1 ... 12.N depends on the permissible value of the ripple current consumption of the step-up / step-down converter 12 voltage.

The diesel generator starter operates as follows.

When the contactor 2 is turned on, the voltage of the battery 1 is simultaneously applied to the excitation current regulator 5 and to the boost/buck converter 12 of the voltage. The control system 8 controls the transistor 5.1 of the excitation current controller 5 in the pulse-width modulation mode and maintains a given current in the excitation winding 6.1.1 of the synchronous generator 6.1 by comparing it with the current value coming from the excitation current sensor 9. When the transistor 5.1 is turned off, the excitation winding current 6.1 closes through the diode 5.3. Simultaneously, the control system 8 includes a step-up/step-down converter 12 voltage in the boost mode. Each voltage cell 12.1, ..., 12.N turns on / off with a phase shift of 360 ° / N, maintaining the specified voltage at the output.

When operating in the voltage boost mode, the control system 8 sequentially turns on transistors 12.1.2, ..., 12.N.2, which short-circuit the corresponding chokes 12.1.5, ..., 12.N.5, while turning off the transistors at the output of each choke 12.1 .5, …, 12.N.5 overvoltage occurs:

U=-L di/dt,

where: L is the inductance of the inductor of each voltage cell;

di/dt is the derivative of the inductor current.

The voltages of each inductor 12.1.5, ..., 12.N.5 through the reverse diodes 12.1.3, ..., 12.N.3 charge the second filter capacitance 10. By changing the turn-on time of transistors 12.1.2, ..., 12.N.2, the control system 8 regulates the voltage at the output of the step-up/step-down voltage converter 12, which is controlled by the second voltage sensor 11. After charging the second filter capacitance 10 to a predetermined value, the control system 8 turns on a three-phase voltage inverter 7, switching transistors 7.1.1 and 7.1.2, ..., 7.3.1 and 7.3.2 in accordance with the algorithm of sinusoidal pulse-width modulation (PWM) , while implementing the inversion mode. At the output of the three-phase voltage inverter 7, a three-phase alternating voltage of variable frequency and amplitude is formed, which is supplied to the power inputs A, B, C of the 6.1 synchronous generator, which starts operating in the motor mode and scrolls the diesel shaft 6.2 mechanically connected to it. After starting the diesel engine 6.2, the generator 6.1 starts to operate normally, generating a three-phase alternating voltage. The control system 8 turns off the three-phase voltage inverter 7 and puts the boost/buck converter 12 into a buck mode. The three-phase alternating voltage from the output of the synchronous generator 6.1 by the reverse diodes 7.1.3 and 7.1.4, ..., 7.3.3 and 7.3.4 of the three-phase voltage inverter 7 is converted into a direct voltage (rectification mode), which charges the second filter capacitance 10 and enters the input step-up/down converter 12 voltage. The control system 8 turns on/off the transistors 12.1.1, ..., 12.N.1 of each voltage cell 12.1, ..., 12.N with a phase shift of 360°/N. When the transistors 12.1.1, ..., 12.N.1 are turned off, the currents of the chokes 12.1.5, ... 12.N.5 are closed through the reverse diodes 12.1.4, ..., 12.N.4. By changing the on/off time of the transistors 12.1.1, ... 12.N.1, the control system 8 generates a predetermined voltage value at the output of the step-up/down converter 12 voltage. The reduced voltage is controlled by the first voltage sensor 4 and is fed to the input of the excitation current regulator 5, which is previously disconnected from the battery 1 by the contactor 2. Simultaneously controlling the step-up / step-down voltage converter 12 and the excitation current regulator 5, the control system 8 maintains the required excitation current of the synchronous generator 6.1 during its normal operation.

The claimed technical result is achieved by eliminating from the device a capacitor-based energy storage device based on supercapacitors, the weight and size parameters of which are commensurate with a battery. In addition, the use of the same chokes 12.1.5, ..., 12.N.5 in voltage cells 12.1, ..., 12.N in the step-up / step-down converter 12 voltage to increase and decrease the input / output voltage also reduces the weight and size of the device starting a diesel generator.

The proposed device for starting a diesel generator was tested as part of the DGU18-9DGM and showed its reliability and efficiency.

Claims (1)

A diesel generator starting device, including a battery connected through a contactor to the first filter tank, to the first voltage sensor and to an excitation current regulator, consisting of a transistor shunted by a reverse diode and connected in series with the diode, a diesel generator set containing a synchronous generator with excitation winding and diesel, a three-phase voltage inverter, a control system, while the output of the excitation current regulator through the excitation current sensor is connected to the excitation winding of a synchronous generator, the power inputs of which are connected to the outputs/inputs of a three-phase voltage inverter containing three identical phase cells, each of which contains two transistors connected in series, shunted by freewheeling diodes, the connection points of which are the corresponding phase outputs / inputs of a three-phase voltage inverter, and the parallel-connected phase cells form positive and negative, respectively inputs/outputs of a three-phase voltage inverter that are shunted by a second filtering capacitance and a second voltage sensor, characterized in that the device is equipped with a step-up/down voltage converter connected between the positive and negative inputs/outputs of the three-phase voltage inverter and the input of the excitation current regulator and consisting of N parallel-connected voltage cells, each of which contains two series-connected transistors, shunted by reverse diodes and connected to the connection points of which are a series-connected inductor and an input current sensor, which form the input / output of a step-up / step-down voltage converter, while information signals from the input current sensors , the excitation current sensor, the first and second voltage sensors are input to the control system, which generates control signals for the excitation current regulator, step-up / step-down voltage converter and three-phase inverter n voltage.

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