RU75794U1 - AUTONOMOUS POWER PLANT - Google Patents

Abstract

The utility model relates to autonomous power plants that produce electricity of a stable frequency and stable voltage at a variable speed of rotation of a primary engine, for example, an internal combustion engine (ICE). The task solved by the utility model is to reduce fuel consumption. Autonomous power station contains a primary engine 1 equipped with a speed controller 2, a synchronous generator 3, driven by a motor 1, a frequency converter 4 mounted at the output of the generator 3, switch 5, a shunt converter 4, a sensor 6 of the engine speed 1, an output sensor 7 active power P and a microprocessor control system 8, to the corresponding inputs of which the outputs of the sensors 6 and 7 are connected. The system 8 is configured to form an output 9 connected to the control mu input of the switch 5, and its output 10, connected to the input of the controller 2, control signals as a function of power P, while in the range P <kP _{n a} disconnecting signal is generated at the output 9 of system 8, at its output 10 a signal corresponding to the optimal to the minimum fuel consumption, the dependences of the rotation speed of engine 1 on its power, and in the range P> kP _n , an output signal 8 is formed at system 9, an inclusion signal, at its output 10, a signal corresponding to the rated speed of engine 1, where R _n is the rated power of the primary engine, k - men than or equal to 1. The system 8 may be provided with an inlet 13 for entering data on the type of the engine 1, and adapted to select by entering the data value k. The sensor 6 can be made in the form of a frequency meter connected to the output of the synchronous generator 3. 2 zpf, 1 il.

Description

Technical field

The utility model relates to the electric power industry and, in particular, to autonomous power plants generating electricity of a stable frequency and stable voltage at a variable speed of rotation of a primary engine, for example, an internal combustion engine (ICE). The utility model can be used, for example, for stand-alone or backup power consumers in areas where centralized power supply is absent or insufficiently reliable.

State of the art

A known device that generates electricity of a stable frequency and a stable voltage, comprising a primary engine equipped with a speed controller, a synchronous generator, a frequency converter installed at the output of the synchronous generator, an output active power sensor, a speed sensor for rotation of the primary engine and a microprocessor control system, to the corresponding inputs which connected the outputs of these sensors, equipped with an output connected to the input of the speed controller first Nogo engine [1].

The disadvantage of the device [1] is the increased fuel consumption due to losses in the frequency converter at a load close to the nominal.

Known autonomous power plant containing an internal combustion engine, a synchronous generator mounted on its shaft, a frequency converter at the output of the synchronous generator and a controlled switch connected between the outputs of the synchronous generator and the frequency converter [2]. The disadvantage of the device [2] is the increased fuel consumption associated with the lack of means for optimal selection of the rotation speed of the primary engine with reduced load.

Utility Model Disclosure

The objective of the utility model is to reduce fuel consumption with the power plant load varying over a wide range.

The technical result achieved by using the utility model consists in saving fuel at a load varying over a wide range, both by optimizing the rotation speed of the primary engine and by eliminating losses in the converter.

The subject of a utility model is an autonomous power plant containing a prime mover equipped with a speed controller, a synchronous generator driven by a prime mover, a frequency converter mounted at the output of a synchronous generator, a switch, a shunt frequency converter, a speed sensor of the prime mover, an output active power sensor P and microprocessor control system, to the corresponding inputs of which the outputs of these sensors are connected, made with POSSIBILITY formation on its first output connected to the control input of the switch and its second output connected to the input of the speed controller of the prime mover, control signals output function F, while in the range R <Kp _n are formed on the first output of the microprocessor control system disables a signal, at its second output, a signal corresponding to the minimum fuel consumption optimum for the dependence of the rotation speed of the primary engine on its power, and in the range P> kP _{n they} are formed at the first output de microprocessor control system - including a signal, at its second output - a signal corresponding to the nominal speed of rotation of the primary engine, where P _n is the rated power of the primary engine, k is less than or equal to 1.

This set of features allows you to solve the problem and get the above technical result.

The development of a utility model for particular cases of its implementation provides that:

- the microprocessor control system may be provided with an input for inputting data on the type of the primary engine, and is configured to select the value k from the input data.

- the primary engine speed sensor can be made in the form of a frequency meter connected to the output of the synchronous generator.

Brief Description of the Drawings

Figure 1 presents a block diagram of an autonomous power plant according to a utility model, taking into account its development.

Utility Model Implementation

The block diagram of figure 1 contains:

1 - a primary engine, for example, a diesel engine;

2 - speed controller of the primary engine 1;

3 - synchronous generator driven by a prime mover;

4 - frequency converter installed at the output of the generator 3;

5 - switch, shunt converter 4;

6 - sensor speed of rotation of the engine 1, made in the form of a frequency sensor of the generator 3;

7 - sensor output active power P connected to the output of the power plant (as sensor 7 can also be used an active power sensor connected to the output of generator 3);

8 - microprocessor control system;

The outputs of the sensors 6 and 7 are connected to the corresponding inputs of the system 8, and its first and second outputs 9 and 10 to the control input of the switch 5 and to the input of the controller 2, respectively. The outputs 11 and 12 of the system 8 control the voltage of the generator 3 (acting on its excitation regulator) and the output frequency of the converter 4, respectively.

The device operates as follows.

The primary engine 1 drives the synchronous generator 3. By acting on the regulator 2, the system 8 changes the speed of rotation of the engine 1. The frequency of the voltage generated by the generator 3, measured by the sensor 6, changes in proportion to the speed of rotation of the engine 1.

From the output of the generator 3, the voltage, the level of which the system 8 can change by influences at the output 11, is supplied to the converter 4, the output frequency of which is maintained within the required limits by the actions given by the system 8 at the output 12.

The control system 8, analyzing the signal from the sensor 7, generates at the outputs 9 and 10 the signals that control the switch 5 and controller 2, respectively.

If the power P measured by the sensor 7 does not exceed a certain value kP _nom , where P _nom is the rated power of the engine 1, ak≤1, the system 8 generates a switching signal at the output 9, which keeps the switch 5 in the open state. In this case, the electric power of the required frequency is supplied to the load from the converter 4, and the system 8 generates a signal at the output 10, which corresponds to the minimum fuel consumption optimum dependence of the rotation speed of the primary engine 1 on its power (first operation mode).

When the power P measured by the sensor 7 is increased to a value of P> kP _nom, system 8 generates a signal at output 9 that turns on the switch 5 and keeps it closed (second mode of operation). In this case, the electric power to the load comes from generator 3, and converter 4 does not work. The closure of the switch 5 is preceded by the formation by the system 8 at the output 10 of the signal corresponding to the nominal speed of rotation of the primary engine 1. This signal, acting on the regulator 2, sets the nominal speed of rotation of the engine 1, which corresponds to the rated frequency of the generator 3 and the required frequency of the alternating voltage at the power plant load.

If the power P measured by the sensor 7 decreases to P <kP _n , the system

control 8 returns the power plant to the first mode of operation.

Fuel economy when performing the device according to the utility model is provided:

- in the first mode (P <kR _nom ), due to the fact that the signal at the output 10 connected to the rotation speed controller 2 is generated by the system 8 in accordance with the optimum dependence of the engine rotation speed 1 on the minimum fuel consumption on its power, changing along with power P, measured by the sensor 7, depending on the magnitude of the electrical load;

- in the second mode (P> kP _nom ) 1 due to the fact that the inclusion of the switch 5 leads the converter 4 from the energy transfer circuit to the load, thereby eliminating the energy loss in it.

As a result of the studies, it was found that the values of k that ensure maximum fuel economy and the type of the minimum fuel consumption dependence of the rotation speed on power are determined by the particular type of internal combustion engine used as engine 1. The k values and the corresponding dependences of the optimal rotation speed on power for various types of internal combustion engines can be pre-entered (for example, at input 13) in the system 8, which is expediently performed be programmable.

Information sources

1. RF patent No. 34817 for utility model. IPC H02J 3/00, 3/46, 2003

2. RF patent No. 45056 for utility model. IPC H02J 3/00, 3/46, 2004

Claims (3)

1. Autonomous power plant containing a primary engine equipped with a speed controller, a synchronous generator driven by a primary motor, a frequency converter mounted at the output of the synchronous generator, a switch, a shunt frequency converter, a speed sensor of the primary motor, an output active power sensor P and microprocessor control system, to the corresponding inputs of which the outputs of these sensors are connected, made with the possibility of forming on the first m its output connected to the control input of the switch and its second output connected to the input prime mover rotation speed control, the control signals to the power P function, the range F <Kp _n are formed on the first output of the microprocessor disables the signal control system, on its second output, a signal corresponding to the optimal minimum fuel consumption dependence of the rotation speed of the primary engine on its power, and in the range P> kP _n are formed at the first output of the microprocessor control system power - including a signal, at its second output - a signal corresponding to the nominal speed of rotation of the primary engine, where R _n is the rated power of the primary engine, k is less than or equal to 1. 2. The stand-alone power plant according to claim 1, characterized in that the microprocessor control system therein is provided with an input for inputting data on the type of primary engine and is configured to select k value from the inputted data. 3. The autonomous power station according to claim 1, characterized in that in it the primary engine speed sensor is made in the form of a frequency meter connected to the output of a synchronous generator.