RU2503580C1 - Ship electric power generator - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: invention relates to ship building. Proposed power generator comprises main engine connected with main generator and local control system. Main generator is connected with propulsion motor via electric circuit including first circuit breaker, main buses, consuming hardware buses, frequency inverter and extra motor/ Extra motor is connected with additional generator connected via second automatic circuit breaker to busses of consuming hardware. Main and extra generators are three-phase electromagnetic excitation generators equipped with first and second phase current output transducers. Local control system can be connected to top level control system, first and second current phase and voltage transducer mounted at consuming equipment buses. Controlled frequency inverter comprises rectifier and inverter connected in series equipped with intrinsic controller. Current sensors connected with controller data input are built in rectifier power output power circuit and inverter input power circuit. Choke is connected to controlled rectifier power input. Choke other output is connected to phase voltage sensor and to third automatic circuit breaker connected to main buses. Phase voltage sensor is connected with rectifier controller. DC link capacitor accumulator and dc voltage sensor connected to both controllers are built in between rectifier output power circuit and inverter input power circuit current sensor. Controllers are connected to selector of operating conditions connected with local control system.

EFFECT: higher efficiency of bus power supply.

1 dwg

Description

The invention relates to the field of shipbuilding, in particular to ship electrical installations with frequency converters and propeller motors. As converters, various circuits are used with uncontrolled rectifiers, which have high energy performance and reliability.

A similar ship electric power plant is known (Grigoryev A.V., Lyapidov K.S., Makarov L.S. Unified electric power plant of a hydrographic vessel based on an alternating current electric propulsion system // Sudostroenie, 2006, No. 4, p. 33-34) containing main diesels, rotating rotors of the main three-phase synchronous generators, the terminals of the stators windings of which are connected via circuit breakers to the three-phase power line of the main switchboard. A well-known marine electric power plant also includes an emergency diesel generator, the three-phase stator winding of which is connected through a circuit breaker to the three-phase line of the emergency switchboard, and the emergency distribution line through the circuit breaker is connected to the three-phase line of the main distribution panel, and a parking diesel generator with three-phase stator winding through a circuit breaker, also connected to the three-phase line of the main distributor st shield. The three-phase line of the main switchboard is connected to the rowing electric drives, consisting of frequency converters, including 12-pulse rectifiers, stand-alone voltage inverters and AC alternating motors with screws mounted on their shafts.

However, in an analogue, rowing electric drives, which are the main consumers of electricity on ships with electric propulsion (the capacity of rowing electric drives may exceed the total capacity of other ship consumers), are fed not directly from the main switchboard line, but through transformers, which reduces the efficiency of the ship’s electric power plant, increases it cost, weight and dimensions.

In addition, this installation has the following disadvantages:

- increased level of harmonics in the current consumed from the network;

- power supply of inverters with unstabilized rectified voltage and the lack of the possibility of energy recovery in the network of ship electrical consumers in shunting modes;

- Electromechanical compensation of reactive power only when the parking generator set of the ship power station is in compensator mode;

- the lack of the possibility of balancing a three-phase system of supply voltages with different loading phases.

Known ship electric power plant (patent No. 2436708, publ. 12/20/2011, authors: Vasin I.M., Senkov A.P., Paperzh Yu.E., Tokarev L.N.), adopted as a prototype containing main diesel engines or turbines and main synchronous generators, the stator windings of which are connected through the circuit breakers to the power line of the main switchboard, frequency converters, each of which consists of a 12-pulse rectifier and an autonomous inverter, to the output of which a rowing electric motor is connected. The installation also includes an emergency diesel generator, the stator winding of which through a circuit breaker is connected to the power line of the emergency switchboard. On the stator of each main generator are placed two similar three-phase windings, the linear voltages of which are offset by 30 electrical degrees. The main switchboard has two three-phase power lines, to each of which three-phase windings of the stators of the main generators are connected via circuit breakers, the linear voltages of which coincide in phase. The two three-phase lines of the main switchboard through the circuit breakers are connected to the inputs of 12-pulse rectifiers that are part of the frequency converters that feed the propeller motors. The primary windings of two three-phase transformers connected by a star are connected to each of the two three-phase lines of the main switchboard through circuit breakers. The secondary winding of the transformer connected to the first three-phase line is connected by a star, and the secondary winding of the second transformer connected to the second line is a triangle. The secondary windings of both three-phase transformers are connected via circuit breakers to the three-phase power line of the switchboard of the remaining ship consumers, to which the stator winding of the parking diesel generator, the three-phase line of the switchboard of the emergency diesel generator, and also the feeders and switchboards of individual ship consumers are connected .

The disadvantages of this installation are:

- the use of non-standard multiphase generators with a more complex electromagnetic excitation system, which should ensure uniform regulation of magnetic fluxes for equal voltage amplitudes in two separate three-phase systems, as well as constructively ensuring the accuracy of the specified phase shifts between the windings, which causes an additional increase in voltage ripples at the output 12- pulse rectifiers, the occurrence of surge currents during synchronous operation with another similar generator;

- increased level of harmonics in the current consumed from the network;

- reduced reliability, efficiency, increased dimensions and weight due to the use of generators with two separate three-phase output voltage systems and sets of equipment for them;

- power supply of inverters with unstabilized rectified voltage and the lack of the possibility of energy recovery in the network of ship electrical consumers in shunting modes;

- electromechanical compensation of reactive power of consumers only with the help of regular generators of a ship power station, transferred to the compensator mode;

- the lack of the possibility of balancing a three-phase system of supply voltages with different loading phases.

The problem solved by the invention is the expansion of the arsenal of funds and the creation of a new marine electric power plant with improved energy characteristics and expanded functionality. Achievable technical result is to enable:

- improving the quality and efficient use of electricity on power buses from the main three-phase generators with electromagnetic excitation due to a controlled rectifier that filters the current consumption, stabilizes the output voltage and the possibility of energy recovery for use by ship consumers;

- the simultaneous use of a controlled rectifier of the frequency converter of this installation as a static reactive power compensator, including for balancing modulo and phase of the voltage vectors in the supply network with different loading of its phases.

The complex task is solved by changing the functional diagram of the installation.

The inventive marine electric power plant includes a main engine connected to a main generator, which is connected to a propeller motor connected to the propeller via an electric circuit including a first circuit breaker, main buses and a frequency converter. The installation also includes power consumer buses connected through a transformer to the main buses, and an additional motor connected to an additional generator, which is connected to the power consumer buses through a second circuit breaker. The installation differs from the prototype in that three-phase generators with electromagnetic excitation are used as the main generator and additional generator, equipped with the first and second phase current sensors, respectively, at the output. The installation also additionally has a local control system, made with the possibility of connecting to a top-level control system, which is not part of the claimed object, but is located outside it. The local control system is connected to the first and second phase current sensors, as well as to a voltage sensor mounted on the buses of electrical consumers. The frequency converter is made controlled reversible and contains serially connected controlled rectifier and inverter, each of which is equipped with its own controller. Current sensors are installed in the output power circuit of the rectifier and the input power circuit of the inverter, each of which is connected to the corresponding information input of the corresponding controller. A choke is connected to the power input of the controlled rectifier, connected by another terminal to a phase voltage sensor and a third circuit breaker, which is connected to the main buses by its other terminal. The phase voltage sensor is connected to the rectifier controller. In the circuit between the current sensor of the output power circuit of the rectifier and the current sensor of the input power circuit of the inverter, a capacitor drive of the DC link is installed, as well as a DC voltage sensor connected to both controllers. Both controllers are also connected to a mode dial associated with the local control system.

The figure shows the installation diagram, which introduced the following notation:

1 - main engine, 2 - additional engine that performs the function of emergency, standby or parking, 3 - main generator, 4 - additional generator, 5 - first circuit breaker, 6 - first phase current sensor, 7 - main buses, 8 - second automatic a switch, 9 - a second phase current sensor, 10 - busbars of electric consumers, 11 - a third circuit breaker, 12 - a frequency converter, reversible and controllable, 13 - a propeller motor, 14 - a fixed-pitch screw, 15 - a fourth circuit breaker, 16 - a transformer, one 7 - fifth circuit breaker, 18 - consumer circuit breakers, 19 - controlled rectifier, 20 - inductor, 21 - first phase current sensor of the frequency converter, 22 - phase voltage sensor, 23 - first DC sensor (current sensor at the output of the rectifier 19) 24 - a capacitor storage device for a DC link, 25 - a DC voltage sensor, 26 - a controlled rectifier controller, 27 - a second DC sensor (current sensor at the inverter input), 28 - an inverter, 29 - a second phase current sensor of the frequency converter, 30 - control inverter 31 - dial mode, the local control system 32, 33 - Phase Voltage sensor mounted on the tire electrical load, 34 - upper-level control system, 35 and 36 - the intersectional breakers.

The ship’s electric power installation comprises a main engine 1 and an additional engine 2, each of which is mechanically connected to its own main electric generator 3 and an additional electric generator 4, which are made three-phase with electromagnetic excitation.

The main generator 3 through the first circuit breaker 5, the first phase current sensor 6 is connected to the main buses 7. The additional generator 4 through the second circuit breaker 8, the second phase current sensor 9 is connected to the buses 10 of the electrical consumers.

The main bus 7 through a third circuit breaker 11 is connected to a power input of a reversible controlled frequency converter 12, the power output of which is connected to a propeller 13, mechanically connected with a fixed-pitch screw 14.

The main bus 7 through the fourth circuit breaker 15, step-down transformer 16 and the fifth circuit breaker 17 are connected to the bus 10 of the consumers, which are connected to the ship's consumers through their circuit breakers 18 (circuit breakers consumers).

The reversible frequency converter 12 in its structure comprises: a controlled rectifier 19, to the power input of which a first phase current sensor 21 of the frequency converter is connected via a choke 20, the opposite power terminals of which are the input of the frequency converter 12, and a phase voltage sensor 22 is connected to them. The power output of the controlled rectifier 19 through the first DC sensor 23 is connected to a capacitor storage 24 DC link. A DC sensor 25 of the controlled rectifier is also connected here. The information circuit of the sensors 21, 22, 23, 25 are connected to the controller 26 of the controlled rectifier 19.

The power input of the inverter 28 is connected to the capacitor drive 24 of the DC link through the second DC sensor 27, and the power output of the inverter 28 through the second phase current sensor 29 of the frequency converter (the opposite power terminals of which are the output of the frequency converter 12) to the stator windings of the outboard motor 13 The control input of the inverter 28 is connected to the output of its controller 30, and the inputs of the latter are connected to the information circuits of the sensors 25, 27, and 29.

The control inputs of the controllers 26 and 30 are connected to the mode dial 31, which is connected via an interface to the local control system 32.

The information inputs of the local control system 32 are connected with the first and second current sensors of phases 6 and 9, as well as with the voltage sensor of phases 33 on the buses of electric consumers.

The local control system 32 is connected via an interface with the control system 34 of the upper level.

The main bus 7 and bus 10 of the electrical consumers using intersectional circuit breakers 35 and 36, and the control system 34 of the upper level via the interface, can be connected respectively to the main tires, bus electrical consumers and local control systems of other similar marine electrical power plants (if any).

Marine electric installation works as follows.

 The signal supplied to the input of the local control system 32 from the control system 34 of the upper level, the installation can be converted into

The following main operating modes:

- modes of movement and braking with compensation of its own reactive power generated in the main tires 7;

- driving and braking modes with reactive power compensation generated on the main tires 7 by a step-down transformer 16 and ship electrical consumers;

- balancing mode modulo and phase voltage on the main buses 7.

In the driving and braking mode with compensation of the own reactive power generated in the main buses 7, the local control system 32, through the mode dial 31, provides reference signals to the controllers 26 and 30 of the reversible frequency converter 12, which put the controlled rectifier 19 in the controlled voltage rectification mode coming from the main buses 7 through the included third circuit breaker 11 and its stabilization on the capacitor storage 24 DC link. At the same time, the inverter 28 is transferred to the formation mode of a three-phase voltage system with the amplitude and frequency determined by the inverter controller 30 in accordance with the principle of vector control of the electric drive.

A rowing electric motor 13 with a fixed pitch propeller is rotated at a predetermined speed control system 34.

In this case, the controlled rectifier 19 in the controlled rectification mode provides a preliminary charge to the capacitor bank 24 and generates a PWM voltage modulated according to a sinusoidal law, and with its help reproduces on the terminals of the inductor 20 a three-phase system of sinusoidal voltage vectors with a given module and a shift angle for each phase, rotating synchronously with a three-phase system of voltage vectors on the main buses 7.

In the output circuit of the controlled rectifier 19, connected through the first DC sensor 23 to the capacitor bank 24, current increases under the control of the controller 26. The DC voltage sensor 25 transmits a voltage feedback signal to the capacitor bank 24 for regulation (stabilization) by the voltage controller 26 at a predetermined level.

At the same time, phase currents increase in the input circuit of the controlled rectifier 19, the amplitudes and phases of which are determined by the vector sum of the voltages on the main buses 7 and the PWM voltages reproduced by the controlled rectifier 19 at its input.

Information about the values of these currents measured by the first phase current sensor 21 in each phase and the line voltages on the main buses 7, through a closed third circuit breaker 11, measured by the phase voltage sensor 22, is presented to the controller 26.

In the controller 26 according to the information received from the sensors 21, 22, 23 and 25, the modules and phase angles of the voltage vectors are calculated, which must be reproduced at the input of the controlled rectifier 19 so that, as a result of the addition of these vectors with the voltage vectors on the main buses 7, between the voltage vector on the main buses 7 and the current vector of the controlled rectifier 19, measured by the phase current sensor 21, was a predetermined angle of shift. To compensate for reactive power on the main buses 7, this angle should be close to zero.

The constant voltage of the capacitor bank 24 is converted under the control of the controller 30, which receives information from the sensors 25, 27 and 29, by the inverter 28 into a PWM voltage to power the three-phase stator windings of the propeller motor 13.

Transfer to the braking mode with compensation of the own reactive power is carried out by a signal from the upper-level control system 34. In this case, the inverter 28 provides the generator mode of the rowing electric motor 13, and the controlled rectifier 19 changes the current direction by 180 electric degrees, the amplitude value of which is set taking into account the load level the main generator 3, determined using the phase current sensor 6. In the absence of included ship consumers, the consumption of braking energy is realized traditionally ny way - by turning on the braking resistors in the DC link of the frequency converter (not shown).

In the driving and braking modes with reactive power compensation generated on the main buses 7 by the transformer 16 and ship consumers, on the instructions of the upper-level control system 34 and the signals of the sensors processed by the local control system 32, the controlled rectifier 19 provides an impedance on the main buses 7, providing the specified the shift angle between the voltage vectors on the main buses and the input current of a reversible frequency converter 12.

In this case, the angle of shift between the vectors of currents and voltages in the corresponding phases of the main generator 3, measured by sensors 21 and 22, will be close to zero.

In the parking, technological or emergency mode of the vessel, its movement and power to ship consumers can be carried out from an additional generator 4 through the included circuit breakers 8, 15, 17 and transformer 16 under the control of the load current of the generator 4 by the second phase current sensor 9.

The mode of balancing modulo and phase of the vectors of the three-phase voltage system on the main buses 7 is carried out according to the signals of the sensor 22 and the formation of a compensating influence controlled by the rectifier 19 under the control of the controller 26. This mode can be performed according to the signal of the upper level control system 34. As described above, the controlled rectifier 19 using the PWM reproduces on the terminals of the inductor 20 a three-phase system of sine voltage vectors with a given module and a shear angle for each phase, rotating synchronously with a three-phase system of voltage vectors on the main buses 7. In this case, the vectors of the three-phase voltage system are aligned in module with mutual phase shift of 120 electrical degrees.

Thus, the use in the invention of a reversible converter with a controlled rectifier and current and voltage feedbacks allows the ship’s electric power plant to operate both in the motor and in the braking mode of the EDMS with energy saving by using the returned electricity by ship’s consumers in traffic control, as well as in emergency, technological and parking conditions. In addition, the circuit allows for voltage stabilization in the DC link and to improve the quality of electricity by compensating with a static converter for reactive power and balancing the voltage module and phase in a three-phase ship’s network at different loads of its phases, which, in turn, increases reliability and operational resource installation as a whole, reduces noise and vibration of electrical equipment.

Claims (1)

Marine electric power plant comprising a main engine connected to a main generator, which, through an electric circuit comprising a first circuit breaker, main buses and a frequency converter, is connected to a propeller motor connected to a propeller, which also contains consumer buses connected via a transformer with the main tires, and containing an additional engine connected to an additional generator, which through the second circuit breaker p It is connected to the buses of electric consumers, characterized in that three-phase generators with electromagnetic excitation are used as the main generator and additional generator, equipped with the first and second phase current sensors respectively, the installation also additionally has a local control system, made possible to connect to the control system top level, the local control system is connected to the first and second phase current sensors, as well as to the voltage sensor, setting to the electric buses, while the frequency converter is made controlled reversible and contains serially connected controlled rectifiers and inverters, each of which is equipped with its own controller, current sensors are installed in the output power circuit of the rectifier and the input power circuit of the inverter, each of which is connected to the corresponding information input of the corresponding controller, a choke is connected to the power input of the controlled rectifier, connected to the phase voltage sensor by another output, and to the third circuit breaker, which is connected to the main buses with its other output, while the phase voltage sensor is connected to the rectifier controller, a capacitor drive of the DC link is installed in the circuit between the current sensor of the output power circuit of the rectifier and the current sensor of the input power circuit of the inverter voltage connected to both controllers, which are also connected to the mode dial associated with the local control system.