RU208094U1 - Diesel generator set load matching module - Google Patents

Abstract

The utility model relates to the field of electrical engineering and is designed to operate as part of a diesel generator set based on a synchronous generator and a turbocharged diesel internal combustion engine. The technical result of the claimed utility model is to increase the reliability of the diesel generator set when starting a turbocharged diesel internal combustion engine, due to the creation of an MSN diesel generator set that provides stepped excitation and smooth voltage recovery of a synchronous generator with adjustable time delays. MSN of a diesel generator set, including a synchronous generator, having a main winding, to which the synchronous generator load is connected through a load switch, an additional winding and an exciter excitation winding, which are connected to a voltage corrector with an installed voltage setting resistor. The input of the MSN is electrically connected to the output of the synchronous generator, and the output of the MSN is electrically connected to the voltage corrector. The control elements of the MSN are: the frequency reduction threshold setting resistor, which sets the frequency threshold at which the MCH is triggered, the voltage reduction setting resistor, which sets the voltage values when the MCH is triggered, the MCH operation mode microswitch, which sets the MCH on / off operation mode, the MCH trip delay microswitch, which sets MCH shutdown delay time for faster recovery of diesel engine speed, step excitation microswitch that sets generator step excitation to reduce generator voltage surge at initial start-up, soft voltage recovery enable microswitch that sets smooth recovery of generator voltage after MCH shutdown, indication unit with LED indicators of normal and rated frequency, which signal the current state of the frequency of the synchronous generator. 1 ill.

Description

The utility model relates to the field of electrical engineering and is designed to operate as part of a diesel generator set based on a synchronous generator and a turbocharged diesel internal combustion engine, including for a diesel internal combustion engine, in which an electronic speed controller with a fixed speed setting and not having external adjustment possibilities. In such installations, the operation of the load balancing module (MCH) has full advantage over other load shedding methods for a turbocharged diesel internal combustion engine under load surge.

From the prior art, there is a method for controlling a diesel generator set when an asynchronous engine is turned on (patent No. 2745149 for invention, IPC Н02Р 1/30, 03/22/2021), according to which when the engine is started, the current increases and the output voltage of the synchronous generator decreases. In case of simultaneous current exceeding and voltage deviation of the set threshold levels, the diesel engine speed controller reduces the diesel generator set speed to the set value and stabilizes it until the asynchronous motor starts at a reduced frequency. After reducing the current and reducing the voltage deviation of the synchronous generator to the preset levels, the regulator of the diesel engine smoothly increases the speed to the nominal value. The voltage of the synchronous generator also increases to the nominal value U _n .

Known technical solutions based on the control of the automatic control of excitation (ARV) generators, focused on mitigating the effects of sudden surges in electrical load. Such control is applied on the produced generators by the company "Leroy-Somer" (Internet resource: https://www.leroy-somer.com/documentation_pdf/4342_ru.pdf. Leroy-Somer. Electric Power Generation. R450. Regulators. Installation and maintenance, p. 12-13), in which a typical excitation system AREP / PMG is supplemented with a LAM module (Load agreement module). The LAM principle presupposes a double effect on the ARV: firstly, a decrease in the voltage setting of the ARV with a significant decrease in the speed and, secondly, a decrease in excitation in proportion to a further decrease in the speed. Both, with a significant surge in load, reduce the voltage, which gives a corresponding decrease in load and thereby facilitates the transient process of the diesel generator set.

The known methods ensure the stabilization of the rotational speed of a diesel internal combustion engine at the output of a synchronous generator at a steady state of operation of the diesel generator set and a smooth increase in frequency when it decreases due to the inclusion of a powerful load.

However, for a diesel generator set, which includes a diesel internal combustion engine with an installed electronic speed controller with a fixed speed setpoint and which does not have the possibility of external adjustment, the use of known technical solutions does not allow a diesel internal combustion engine with a turbocharger to simultaneously take 100% of its load. rated power with subsequent restoration to rated speed.

In such a diesel generator set, the operation of the load balancing module (MCH) according to the claimed solution has a complete advantage over other methods of reducing the load for a turbocharged diesel internal combustion engine under load surge.

It is known that most turbocharged diesel internal combustion engines, due to the specifics of their operation, can simultaneously take no more than 50% of the load of their rated power. Under higher load, the diesel internal combustion engine may not restore its speed to the nominal values or stall. In order for a turbocharged diesel internal combustion engine to be able to simultaneously take 100% of the load of its rated power with subsequent restoration to rated speed, the declared MCH has been developed.

Thus, a disadvantage of the known diesel generator sets consists in the insufficient reliability of the operation of the diesel generator set when starting the diesel internal combustion engine with a turbocharger.

The task to be solved by the present utility model is to create a load matching module for a diesel generator set, which performs not only its main function of restoring the speed of a turbocharged diesel internal combustion engine, but also the function of step excitation and smooth recovery of the generator voltage synchronous with adjustable time delays.

The technical task is to create a load matching module for a diesel generator set, which provides step excitation and smooth recovery of the voltage of a synchronous generator with adjustable time delays.

This goal is achieved by the fact that the load matching module of a diesel generator set, which includes a synchronous generator, has a main winding, to which the load of the synchronous generator is connected through a load break switch, an additional winding and an exciter field winding, which are connected to a voltage corrector with a voltage setting resistor installed, characterized by the fact that the MCH input is electrically connected to the output of the synchronous generator, and the MCH output is electrically connected to the voltage corrector, while the MCH regulating elements are: the frequency reduction threshold setting resistor, which sets the frequency threshold at which the MCH is triggered, the reduction setting resistor voltage, which sets the voltage values when the MCH is triggered, the microswitch of the MCH operating mode, which sets the operating mode of the MCH on / off, the microswitch of the delayed disconnection of the MCH, which sets the delay time for the disconnection of the MCH for faster speed recovery of the diesel engine, a step excitation microswitch, which sets the step excitation of the generator to reduce the generator overshoot at the initial start, a microswitch for enabling a smooth voltage recovery, which sets a smooth recovery of the generator voltage after switching off the MCH, an indication unit with LED indicators of normal and nominal frequency, which signal the current state of the frequency of the synchronous generator.

With a simultaneous load surge and a decrease in the speed of the diesel internal combustion engine below the threshold value, the MCH provides a sharp decrease in the generator voltage, thereby reducing the load on the diesel internal combustion engine, which in turn allows the diesel internal combustion engine to restore the speed to the nominal value, with subsequent restoration generator voltage.

On the example of power plants with an industrial frequency of 50 Hz and a voltage of 400 V, with a one-stage surge of 100% of the load, the speed of the diesel engine decreases, and, consequently, the frequency of the generator. When the frequency of the synchronous generator decreases below 47.5 Hz, the MCH sends a signal to the voltage corrector, reducing the output voltage of the synchronous generator by 25% Un, i.e. up to 300 V. When the voltage of the synchronous generator decreases by 25%, the load current also decreases by 25%, which leads to a decrease in the power of the diesel internal combustion engine by 50%. With such a decrease in power, the diesel internal combustion engine begins to reach its rated speed. When the frequency reaches 47.5 Hz and above, the MCH removes the signal from the voltage corrector, and the voltage of the synchronous generator is restored to the nominal values of 400 V.

The utility model is illustrated by the following graphic material.

in fig. - a schematic diagram of a diesel generator set is presented, where:

1 - synchronous generator;

2 - the main winding of the synchronous generator;

3 - additional winding of the synchronous generator;

4 - excitation winding of the exciter of the synchronous generator;

5 - voltage corrector;

6 - resistor for setting the voltage of the synchronous generator;

7 - load switch;

8 - load of the synchronous generator;

9 - load matching module;

10 - matching transformer;

11 - power supply unit;

12 - shaper of rectangular pulses;

13 - triangular pulse shaper;

14 - resistor for setting the frequency reduction threshold;

15 - comparator;

16 - amplitude detector;

17 - microswitch of the MSN operating mode;

18 - delay line for switching on in the operation of the MCH;

19 - unit for permitting the operation of the MSN;

20 - indication unit;

21 - indicator of normal frequency;

22 - frequency reduction indicator;

23 - microswitch of the MCH off delay;

24 - MCH off delay line;

25 - microswitch of the step excitation mode;

26 - stepwise excitation delay line;

27 - adder;

28 - voltage reduction setting resistor;

29 - microswitch for enabling smooth voltage recovery;

30 - integrator;

31 - amplifier of the output signal;

32 - communication with the generator;

33 - communication with a voltage corrector;

34 - diesel internal combustion engine. The device works as follows.

The synchronous generator 1 has a main winding 2, an additional winding 3 and a field winding of the exciter 4, which are connected to a voltage corrector 5. A voltage setting resistor is installed in the voltage corrector 5. The voltage corrector 5 ensures the stability of the output voltage of the synchronous generator 1 at the voltage setting 6 set by the resistor generator synchronous 1 level. To the main winding 2 of the synchronous generator 1, through the load switch 7, the load 8 of the synchronous generator 1 is connected.

The output voltage of the synchronous communication generator 32 is fed to the matching transformer 10 MCH 9. From the output of the matching transformer 10, the voltage is supplied to the power unit 11, which provides power to the MCH 9 circuit and to the square-wave former 12. 13 and further to the comparator 15. The comparator 15 compares the rectangular signal from the triangular shaper 13 and the signal from the frequency reduction threshold setting resistor 14. When the frequency of the synchronous generator 1 changes, the amplitude of the triangular pulses of the triangular pulse generator 13 changes. 1 below the set threshold, short pulses appear at the output of the comparator 15, which are fed to the amplitude detector 16, expand and obtain a constant amplitude signal waveform. Thus, when the frequency of the synchronous generator 1 drops below the set threshold, a frequency reduction signal appears at the output of the amplitude detector 16.

The microswitch 17 of the mode of operation of the load balancing module sets the on / off mode. In the disabled position, the unit for enabling the operation of 19 of the load balancing module blocks the passage of the frequency reduction signal from the amplitude detector 16 and MCH 9 does not work. When the MCH 9 operating mode is on, in order to avoid false triggering during the initial start of the synchronous generator 1, the MCH 9 operation is blocked for the time determined by the delay line for switching on the load matching module 18.

From the output of the operation permitting unit 19, the signal goes to the display unit 20, in which the LED indicator of the normal frequency 21 and the indicator of the decrease in frequency 22 signal the current state of the frequency of the synchronous generator 1.

When the frequency of the synchronous generator 1 drops below the set threshold, the frequency reduction signal through the microswitch 23 of the disconnection delay of the load balancing module and the disconnection delay line of the load balancing module 24 is fed to the adder 27. When the microswitch 23 is disconnected, the disconnection delay of the load balancing module, after the loss of the frequency reduction signal, the operation of MCH 9 stops without time delay and the voltage of the synchronous generator 1 is quickly restored. When the microswitch 23 is turned on for the disconnection delay of the load matching module, after the loss of the frequency reduction signal, the operation of the MCN 9 stops after a time specified by the disconnection delay line 24 of the load matching module and the voltage of the synchronous generator 1 is restored with a time delay, thereby allowing faster recovery of revolutions.

MCH 9 has a step excitation mode. When the microswitch 25 of the step excitation mode is turned off, the voltage is quickly restored. When the microswitch 25 of the step excitation mode MCH 9 is turned on, upon initial excitation, it immediately turns on and sets the voltage of the synchronous generator 1 at the level set by the voltage reduction setpoint resistor 28, and after a time determined by the step excitation delay line 26, it is restored to the voltage setpoint set by the resistor 6 of the synchronous generator 1. Thus, the excitation of the synchronous generator 1 occurs in two stages without overvoltage.

From the output of the adder 27, the signal is fed to the voltage reduction setting resistor 28, which sets the voltage value when the MCH 9 is triggered.

From the output of the voltage reduction setting resistor 28, the frequency reduction signal, through the integrator 30 and the microswitch 29 for enabling the smooth voltage recovery, is fed to the output signal amplifier 31. When the microswitch 29 is turned off, the smooth recovery of voltage is enabled, after the frequency lowering signal is removed, the voltage of the synchronous generator 1 is quickly restored to the preset value. When the position of the microswitch 29 is turned on for smooth voltage recovery, after removing the frequency reduction signal, the voltage of the synchronous generator 1 is smoothly restored to the preset value. The smooth voltage recovery time is determined by the parameters of the integrator 30. The smooth voltage recovery additionally accelerates the recovery time of the frequency of the synchronous generator 1, and hence the speed of the diesel internal combustion engine 34.

From the output of the amplifier of the output signal 31 in communication with the voltage corrector 33, the MCH 9 operation signal is fed to the voltage setting resistor of the generator 6, as a result of which the voltage of the synchronous generator 1 is reduced to the voltage reduction setting set by the resistor 28. After the frequency of the synchronous generator 1 is restored, and therefore , and the speed of the diesel internal combustion engine, the voltage of the synchronous generator 1 is restored to the set value

Thus, MCH 9 performs not only its main function of restoring the speed of the turbocharged diesel internal combustion engine 34, but also the function of step excitation and smooth recovery of the voltage of the synchronous generator 1 with adjustable time delays.

Claims (1)

The load matching module of a diesel generator set, including a synchronous generator, has a main winding, to which the generator load, an additional winding and an exciter field winding are connected through a load breaker, which are connected to a voltage corrector with a voltage setting resistor, characterized by the fact that the MCH input is electrical connection is connected to the output of the synchronous generator, and the output of the MCH is electrically connected to the voltage corrector, while the MCH circuit includes regulating elements: the frequency reduction threshold setting resistor, which sets the frequency threshold at which the load matching module is triggered, the voltage reduction setting resistor, setting the voltage values when the load matching module is triggered, the microswitch of the load matching module operating mode, which sets the operating mode of the load matching module on / off, the microswitch of the module shutdown delay according to load matching, which sets the delay time for switching off the load matching module to quickly restore the revolutions of the diesel internal combustion engine, the step excitation microswitch setting the step excitation of the synchronous generator to reduce the voltage overshoot of the synchronous generator at the initial start, the microswitch for enabling smooth voltage recovery, setting the smooth recovery of the generator voltage after disconnection of the load matching module, an indication unit with LED indicators of normal and underfrequency, which signal the current state of the synchronous generator frequency.

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