阅读说明：本技术 一种增强燃气发电机组突变负载能力的系统及控制方法 (System for enhancing sudden load capacity of gas generator set and control method ) 是由 黄翔 李万钊 杨志勇 张培 郭鹏 蔡博 沈锐 张旺林 顾敬虎 盛建兴 戴峭峰 于 2019-09-03 设计创作，主要内容包括：本发明公开了一种增强燃气发电机组突变负载能力的系统及控制方法,所述系统包括原动机、原动机控制器、异步电动机和发电机,所述燃气发电机组上分别设置有扭矩传感器和测速传感器,扭矩传感器和测速传感器分别连接原动机控制器,发电机的三相输出线路上连接有UPS不间断电源,UPS不间断电源的三相输出端对应连接交流调压装置的三相输入端,交流调压装置的三相输出端对应连接至异步电动机的三相接入端,且在交流调压装置的三相输出端与异步电动机的三相接入端之间设置有一组由第一继电器组控制的继电器触点,原动机控制器与交流调压装置之间连接有控制交流调压装置输出的第一CAN总线,且第一CAN总线通过电压信号输出线连接至第一继电器组的控制端。(The invention discloses a system for enhancing sudden load capacity of a gas generator set and a control method, the system comprises a prime motor, a prime motor controller, an asynchronous motor and a generator, wherein the gas generator set is respectively provided with a torque sensor and a speed sensor which are respectively connected with the prime motor controller, a three-phase output line of the generator is connected with a UPS, the three-phase output end of the UPS is correspondingly connected with the three-phase input end of an AC voltage regulating device, the three-phase output end of the AC voltage regulating device is correspondingly connected with the three-phase access end of the asynchronous motor, a group of relay contacts controlled by a first relay group are arranged between the three-phase output end of the AC voltage regulating device and the three-phase access end of the asynchronous motor, a first CAN bus for controlling the output of the AC voltage regulating device is connected between the prime motor controller and the, and the first CAN bus is connected to the control end of the first relay group through a voltage signal output line.)

1. The utility model provides a system for reinforcing gas generating set sudden change load capacity, its characterized in that includes as gas engine's prime mover, is used for control the prime mover controller of prime mover, connects gradually the asynchronous machine and the generator of prime mover, asynchronous machine's rotor with the rotor of generator all with the output shaft coaxial coupling of prime mover, gas generating set is last still to be provided with the torque sensor and the tachometer sensor that are used for detecting the output shaft moment of torsion and the output shaft rotational speed of prime mover respectively, torque sensor and tachometer sensor connect respectively the prime mover controller, be connected with UPS uninterrupted power source on the three-phase output line of generator, UPS uninterrupted power source's three-phase output corresponds the three-phase input of connecting AC voltage regulator, AC voltage regulator's three-phase output corresponds and is connected to asynchronous machine's three-phase incoming end, a group of relay contacts controlled by a first relay group are arranged between the three-phase output end of the alternating current voltage regulating device and the three-phase access end of the asynchronous motor, a first CAN bus for controlling the output of the alternating current voltage regulating device is connected between the prime mover controller and the alternating current voltage regulating device, and the first CAN bus is connected to the control end of the first relay group through a voltage signal output line; wherein, the relay quantity of first relay group is three.

2. The system for enhancing sudden change load capacity of a gas generator set according to claim 1, wherein a direct current voltage regulator is connected to a three-phase output line of the generator, the direct current voltage regulator is provided with a direct current positive terminal, a direct current negative terminal and two control signal voltage output terminals, two of three-phase input ends of the asynchronous motor are connected to the direct current positive terminal and the direct current negative terminal respectively, a set of relay contacts controlled by a second relay set is arranged between the two phase input ends and the direct current positive terminal and the direct current negative terminal, and the two control signal voltage output terminals are connected to a control end of the second relay set; and the number of the relays of the second relay group is two.

3. The system for enhancing sudden load capability of a gas generator set according to claim 1, wherein the ac voltage regulator comprises three pairs of thyristors connected in reverse parallel for passing through the phase line current, and one end of the thyristors connected in reverse parallel is an input end of the dc voltage regulator, and the other end is an output end of the dc voltage regulator.

4. The system for enhancing sudden load capacity of the gas generator set according to claim 1, wherein the direct current voltage regulating device comprises a voltage reduction module, a rectification filter module and a linear voltage regulation module which are sequentially connected from input to output.

5. The system for enhancing sudden load capacity of a gas generator set according to claim 1, further comprising an asynchronous generator control device for converting the asynchronous motor into an asynchronous generator, wherein the asynchronous generator control device comprises three groups of capacitors connected to three-phase access terminals of the asynchronous motor and connected in delta connection or star connection, and a group of relay contacts controlled by a third relay group are arranged between the three-phase access terminals and the three groups of capacitors; and the number of the relays of the third relay group is three.

6. The system for enhancing sudden load capability of a gas-fired power plant according to claim 1, wherein the asynchronous motor is an asynchronous water-cooled motor.

7. The system for enhancing sudden load capacity of a gas generator set according to any one of claims 1, 2 and 5, wherein the relay is a solid state relay.

8. A control method of a system for enhancing sudden load capacity of a gas generator set according to any one of claims 1 to 7, characterized by comprising the following steps:

(1) an asynchronous motor is arranged in the gas generator set, and a rotor of the asynchronous motor is coaxially connected with a rotor of a generator and an output shaft of a prime mover in the gas generator set;

(2) a torque sensor and a speed measuring sensor for detecting the torque and the rotating speed of an output shaft of a prime motor are respectively arranged in the gas generator set;

(3) the UPS is connected with a three-phase output circuit of the generator, and the AC voltage regulating device is connected with the UPS;

(4) setting the maximum allowable torque increase rate of the engine to be X%, and setting the maximum allowable unloaded torque variation of the engine to be M%;

(5) establishing the following judgment formula for identifying the load state of the gas generator set: beta ═ T_n+1－T_n)÷T_n×100％；

Wherein beta is an enginePercent change in torque, T_n+1And T_nThe engine output shaft torque of the next time end point and the engine output shaft torque of the previous time end point in the time interval from starting to stopping of the unit operation are respectively obtained;

(6) judging the load state of the gas generator set according to the following method: when the beta value is larger than X%, the unit is in a sudden loading state; when the beta value is smaller than M%, the unit is in a sudden unloading state; when the beta value is between M% and X%, the unit is in an idle load or stable loading state;

(7) when the gas generator set is in a sudden loading state, so that the rotating speed of an output shaft of the prime mover is reduced, the UPS and the AC voltage regulator are used for supplying power to the asynchronous motor, and the asynchronous motor generates a torque in the same direction as the prime mover, so that the rotating speed of the output shaft of the prime mover is increased; when the gas generator set reaches a stable loading state, the connection between the alternating current voltage regulating device and the asynchronous motor is disconnected, so that power supply to the asynchronous motor is stopped.

9. The method for controlling the system for enhancing sudden load capacity of the gas generator set according to claim 8, further comprising the following steps:

(1) a direct current voltage regulating device connected with a three-phase output circuit of the generator is arranged;

(2) when the gas generator set is in a sudden unloading state, so that the rotating speed of the output shaft of the prime mover is increased, the direct-current voltage is output by the direct-current voltage regulating device and loaded to two phase line access ends of three-phase access ends of the asynchronous motor, and a direct-current excitation voltage is supplied to a stator winding of the asynchronous motor, so that energy consumption braking is realized, and the rotating speed of the output shaft of the prime mover is reduced; when the gas generator set reaches a stable loading state, the connection between the direct current voltage regulating device and the asynchronous motor is disconnected, and therefore the energy consumption braking of the asynchronous motor is stopped.

10. The method of claim 8, further comprising a type selection of the asynchronous motor, wherein the type selection of the asynchronous motor comprises a selection of a rated speed of the asynchronous motor and a selection of a rated power of the asynchronous motor; the rated rotating speed of the asynchronous motor is selected to be the same as the rated rotating speed of the generator, and the rated power of the asynchronous motor is selected according to the following method:

(1) establishing an output torque change curve of the engine of the gas generator set during slow loading through a test;

(2) establishing an output torque change curve of the engine of the gas generator set during sudden loading through a test;

(3) establishing an output torque change curve of the engine when the gas generator set is suddenly unloaded through a test;

(4) determining the rated torque of the required asynchronous motor according to the three torque change curves;

(5) the rated power of the asynchronous motor is obtained according to the following formula:

T_N＝9550×P_n÷n_N，

wherein, T_NFor rated torque of asynchronous motors, P_nFor rated power of asynchronous motor, n_NThe rated rotating speed of the asynchronous motor.

Technical Field

The invention relates to the technical field of gas generator sets, in particular to a system for enhancing sudden load capacity of a gas generator set and a control method.

Background

The gas generator is a new energy generator which uses combustible gas such as liquefied gas, natural gas and the like as a comburent to replace gasoline and diesel oil as engine power.

The existing gas generator set is limited by fuel properties, the sudden loading capacity and the sudden unloading capacity of the gas generator set are generally kept in a lower range of 10% -20%, and the capacity of suddenly loading a larger load and the capacity of suddenly unloading a larger load cannot be borne, so that the gas generator set with power which is 3-5 times larger than that of an electric load is often selected. Therefore, on one hand, the volume of the whole gas generator set is increased, and on the other hand, the cost of the gas generator set is also increased.

Disclosure of Invention

In order to solve the problems, the invention provides a system for enhancing sudden load capacity of a gas generator set and a control method thereof, aiming at improving the bearing capacity of the gas generator set for sudden load change and reducing the volume and the cost of the gas generator set. The specific technical scheme is as follows:

the utility model provides a system for reinforcing gas generating set sudden change load capacity, includes as gas engine's prime mover, is used for control the prime mover controller of prime mover, connects gradually the asynchronous motor and the generator of prime mover, asynchronous motor's rotor with the rotor of generator all with the output shaft coaxial coupling of prime mover, still be provided with the torque sensor and the tachometer sensor that are used for detecting the output shaft moment of torsion and the output shaft rotational speed of prime mover on the gas generating set respectively, torque sensor and tachometer sensor connect respectively the prime mover controller, be connected with UPS uninterrupted power source on the three-phase output line of generator, UPS uninterrupted power source's three-phase output end corresponds the three-phase input of connecting AC voltage regulator, AC voltage regulator's three-phase output end corresponds and is connected to asynchronous motor's three-phase access end, a group of relay contacts controlled by a first relay group are arranged between the three-phase output end of the alternating current voltage regulating device and the three-phase access end of the asynchronous motor, a first CAN bus for controlling the output of the alternating current voltage regulating device is connected between the prime mover controller and the alternating current voltage regulating device, and the first CAN bus is connected to the control end of the first relay group through a voltage signal output line; wherein, the relay quantity of first relay group is three.

In the technical scheme, the output shaft torque and the output shaft rotating speed of the prime motor are respectively detected by the prime motor controller through the torque sensor and the speed measuring sensor, when the gas generator set is in a sudden loading state, the output shaft torque of the prime motor is increased, and the rotating speed is reduced, so that the prime motor controller sends out a control signal and supplies power to the asynchronous motor through the UPS (uninterrupted power supply) and the AC voltage regulator, and the asynchronous motor generates a torque in the same direction as the prime motor, so that the rotating speed of the output shaft of the prime motor is increased; when the gas generator set reaches a stable loading state, the output shaft torque and the rotating speed of the prime motor are recovered to be normal, the prime motor controller sends out a control signal, and the connection between the alternating current voltage regulating device and the asynchronous motor is disconnected, so that the power supply to the asynchronous motor is stopped.

As a further improvement of the present invention, a dc voltage regulator is connected to a three-phase output line of the generator, the dc voltage regulator is provided with a dc positive terminal, a dc negative terminal and two control signal voltage output terminals, two of the three-phase access terminals of the asynchronous motor are connected to the dc positive terminal and the dc negative terminal, a set of relay contacts controlled by a second relay group is provided between the two phase access terminals and the dc positive terminal and the dc negative terminal, and the two control signal voltage output terminals are connected to the control terminal of the second relay group; and the number of the relays of the second relay group is two.

When the gas generator set is in a sudden unloading state, the torque of an output shaft of the prime motor is reduced, and the rotating speed is increased, so that the prime motor controller sends a control signal, and outputs direct-current voltage through the direct-current voltage regulating device, the direct-current voltage is loaded to two phase line access ends of three-phase access ends of the asynchronous motor, and a direct-current excitation voltage is supplied to a stator winding of the asynchronous motor, so that the energy consumption braking is realized, and the rotating speed of the output shaft of the prime motor is reduced; when the gas generator set reaches a stable loading state, the torque and the rotating speed of the output shaft of the prime motor are recovered to be normal, the prime motor controller sends out a control signal to disconnect the direct-current voltage regulating device from the asynchronous motor, and therefore the energy-consumption braking of the asynchronous motor is stopped.

As a preferred scheme of the ac voltage regulating device in the present invention, the ac voltage regulating device includes three pairs of thyristors connected in reverse parallel respectively for passing through phase line currents, and one end of the thyristor connected in reverse parallel is an input end of the dc voltage regulating device, and the other end is an output end of the dc voltage regulating device.

The alternating current voltage regulating device adopts the thyristors in the reverse parallel connection, so that each pair of thyristors in the reverse parallel connection CAN realize the bidirectional conduction of alternating current under the triggering of a CAN bus signal.

In addition, a group of relay contacts controlled by a first relay group are arranged between the three-phase output end of the alternating current voltage regulating device and the three-phase access end of the asynchronous motor, and the first relay group is controlled by a CAN bus signal, so that the UPS is switched on or off.

As a preferable scheme of the dc voltage regulation device in the present invention, the dc voltage regulation device includes a voltage reduction module, a rectification filter module, and a linear voltage stabilization module, which are sequentially connected in order from input to output.

As a further improvement, the system for enhancing sudden change load capacity of a gas generator set of the present invention further comprises an asynchronous generator control device for converting the asynchronous motor into an asynchronous generator, wherein the asynchronous generator control device comprises three groups of capacitors connected to a three-phase access terminal of the asynchronous motor and connected in a delta connection or a star connection, and a group of relay contacts controlled by a third relay group is arranged between the three-phase access terminal and the three groups of capacitors; and the number of the relays of the third relay group is three.

The asynchronous motor can be used as an asynchronous generator by arranging the asynchronous generator control device, so that a power supply can be provided for core equipment under the condition that the main generator fails.

Preferably, the asynchronous motor in the invention is an asynchronous water-cooled motor.

The asynchronous motor is preferably an asynchronous water-cooled motor, the overload capacity and the heat dissipation capacity of the asynchronous water-cooled motor are better, and the asynchronous water-cooled motor is beneficial to a gas generator set to adapt to severe working conditions with larger heat productivity caused by frequent and sudden loading and unloading of the gas generator set.

Preferably, the relay in the present invention is a solid state relay.

A control method of a system for enhancing sudden load capacity of a gas generator set comprises the following steps:

(1) an asynchronous motor is arranged in the gas generator set, and a rotor of the asynchronous motor is coaxially connected with a rotor of a generator and an output shaft of a prime mover in the gas generator set;

(2) a torque sensor and a speed measuring sensor for detecting the torque and the rotating speed of an output shaft of a prime motor are respectively arranged in the gas generator set;

(3) the UPS is connected with a three-phase output circuit of the generator, and the AC voltage regulating device is connected with the UPS;

(4) setting the maximum allowable torque increase rate of the engine to be X%, and setting the maximum allowable unloaded torque variation of the engine to be M%;

(5) establishing the following judgment formula for identifying the load state of the gas generator set: beta ═ T_n+1－T_n)÷T_n×100％；

Where β is the percent change in torque of the engine, T_n+1And T_nThe engine output shaft torque of the next time end point and the engine output shaft torque of the previous time end point in the time interval from starting to stopping of the unit operation are respectively obtained;

(6) judging the load state of the gas generator set according to the following method: when the beta value is larger than X%, the unit is in a sudden loading state; when the beta value is smaller than M%, the unit is in a sudden unloading state; when the beta value is between M% and X%, the unit is in an idle load or stable loading state;

(7) when the gas generator set is in a sudden loading state, so that the rotating speed of the output shaft of the prime mover is reduced, the UPS and the AC voltage regulator are used for supplying power to the asynchronous motor, and the asynchronous motor generates a torque in the same direction as the prime mover, so that the rotating speed of the output shaft of the prime mover is increased; when the gas generator set reaches a stable loading state, the connection between the alternating current voltage regulating device and the asynchronous motor is disconnected, so that power supply to the asynchronous motor is stopped.

As a further improvement, the control method of the system for enhancing sudden load capacity of the gas generator set further comprises the following steps:

(1) a direct current voltage regulating device connected with a three-phase output circuit of the generator is arranged;

(2) when the gas generator set is in a sudden unloading state, so that the rotating speed of the output shaft of the prime mover is increased, the direct-current voltage is output by the direct-current voltage regulating device and loaded to two phase line access ends in three-phase access ends of the asynchronous motor, and a direct-current excitation voltage is supplied to a stator winding of the asynchronous motor, so that energy consumption braking is realized, and the rotating speed of the output shaft of the prime mover is reduced; when the gas generator set reaches a stable loading state, the connection between the direct current voltage regulating device and the asynchronous motor is disconnected, and therefore the energy consumption braking of the asynchronous motor is stopped.

As a further improvement, the control method of the system for enhancing sudden load capacity of the gas generator set further comprises the step of selecting the type of the asynchronous motor, wherein the selection of the type of the asynchronous motor comprises the selection of the rated rotating speed of the asynchronous motor and the selection of the rated power of the asynchronous motor; wherein the rated speed of the asynchronous motor is selected to be the same as the rated speed of the generator, and the rated power of the asynchronous motor is selected according to the following method:

(1) establishing an output torque change curve of the engine of the gas generator set during slow loading through a test;

(2) establishing an output torque change curve of the engine of the gas generator set during sudden loading through a test;

(3) establishing an output torque change curve of the engine when the gas generator set is suddenly unloaded through a test;

(4) determining the rated torque of the required asynchronous motor according to the three torque change curves;

(5) the rated power of the asynchronous motor is obtained according to the following formula: t is_N＝9550×P_n÷n_N，

Wherein, T_NFor rated torque of asynchronous motors, P_nFor rated power of asynchronous motor, n_NThe rated rotating speed of the asynchronous motor.

The invention has the beneficial effects that:

first, according to the system and the control method for enhancing sudden load capability of the gas generator set, when the gas generator set is in a sudden loading state, the UPS and the AC voltage regulator connected to the three-phase output line of the generator set can be used for supplying power to the asynchronous motor, the asynchronous motor generates a torque in the same direction as the prime motor, so that the output shaft rotating speed of the prime motor is increased, and the bearing capability of the gas generator set for sudden load increase is improved.

Secondly, according to the system and the control method for enhancing the sudden load capacity of the gas generator set, when the gas generator set is in a sudden unloading state, direct-current voltage can be output through the direct-current voltage regulating device connected to the three-phase output circuit of the generator, and direct-current excitation voltage is supplied to the stator winding of the asynchronous motor, so that energy consumption braking is achieved, the output shaft rotation speed of the prime motor is reduced, and the bearing capacity of the gas generator set for sudden load reduction is improved.

Thirdly, according to the system and the control method for enhancing the sudden change load capacity of the gas generator set, the asynchronous motor can be used as the asynchronous generator by arranging the control device of the asynchronous generator, so that the power supply can be provided for the core equipment under the condition that the main generator fails.

Fourthly, according to the system and the control method for enhancing the sudden load capacity of the gas generator set, the asynchronous motor is preferably an asynchronous water-cooled motor, the overload capacity and the heat dissipation capacity are better, and the gas generator set is more suitable for the severe working condition with larger heat productivity caused by frequent sudden loading and unloading.

Fifthly, according to the system for enhancing the sudden load capacity of the gas generator set and the control method, the design and the model selection of the gas generator set are optimized by establishing the output torque change curve of the engine of the gas generator set under the working conditions of slow loading, sudden loading and sudden unloading, so that the adaptability of the gas generator set to the sudden load is further improved.

Drawings

FIG. 1 is a schematic illustration of a complete plant of a system for enhancing the sudden load capability of a gas-fired power plant of the present invention;

FIG. 2 is a schematic circuit diagram of a system for enhancing sudden load capability of a gas-fired power generating unit in accordance with the present invention;

FIG. 3 is a large view of the left half of FIG. 2;

FIG. 4 is a schematic view of the right half of FIG. 2;

FIG. 5 is a graphical illustration of the output torque variation of an engine with a slow load of a conventional gas turbine generator set;

FIG. 6 is a graphical illustration of the output torque variation of the engine during sudden loading of a conventional gas turbine generator set;

FIG. 7 is a graphical illustration of the output torque variation of the engine during sudden unloading of a conventional gas turbine generator set;

FIG. 8 is a schematic diagram of a system for enhancing sudden load capability of a gas generator set according to the present invention, in which a closed-loop speed regulation method is adopted to enhance sudden load capability;

FIG. 9 is a schematic diagram of a unit under sudden loading and controlled by a closed loop speed regulation system;

FIG. 10 is a schematic diagram of a unit under sudden unloading control using a closed loop governing system;

FIG. 11 is a schematic wiring diagram for dynamic braking of an asynchronous motor;

fig. 12 is a schematic diagram of three groups of capacitors connected in a delta connection on three phases of a stator of an asynchronous generator.

In the figure: g is a generator, M is an asynchronous motor, ECU is a prime mover controller (engine ECU), K1, K2 and K3 are three solid-state relays in a third relay group, K4, K5 and K6 are three solid-state relays in a first relay group, and K7 and K8 are three solid-state relays in a second relay group.

Detailed Description

The following description will further describe embodiments of the present invention with reference to the accompanying drawings and examples. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.