Power control circuit for proportional linear voltage drop during overload of generator

Abstract

The utility model provides a power control circuit for proportionally and linearly reducing voltage when a generator is overloaded. The power control circuit comprises an excitation voltage input end, the excitation voltage input end is connected with an excitation voltage rectification unit, the excitation voltage rectification unit is connected with a sampling voltage input potentiometer, and the sampling voltage input potentiometer is connected with a sampling voltage output potentiometer. The sampling voltage input potentiometer is connected with the negative end input of the sampling voltage given control unit, the excitation voltage rectification unit is connected with a motor excitation coil, and the excitation voltage rectification unit is connected with a reference voltage regulator tube through a current-limiting resistor. Current and voltage formed by the excitation current and voltage sampling resistor and given voltage of the reference voltage regulator tube are input into the current feedback given control unit for comparison, if the current and voltage are larger than the given voltage, the excitation current is reduced, otherwise, the excitation current is increased, and the output power of the excitation current is kept unchanged; and the working state of the generator is stable without overload.

Description

Technical Field

[0001] The utility model belongs to the technical field of generator circuits, and particularly relates to a power control circuit for linearly decreasing the voltage of a generator in proportion to overload. Background Art

[0002] The utility model relates to the generator circuit control industry, which refers to converting the energy generated by other forms of gasoline, diesel engines, or other energy power machinery into mechanical energy and transmitting it to the generator, and then the generator converts it into electrical energy. At present, the generator only has a voltage stabilization function but does not have an overload working function. Once overloaded, the motor will heat up, the power fatigue will not work normally, especially when the starting current of the inductive load and the capacitive load is large, the generator cannot do the job well, and it cannot be overloaded to work as usual. If it is overloaded, the machine will heat up and be damaged. Under this technical background, the inventor has designed a power control circuit that linearly reduces the voltage in proportion to the generator overload. Utility Model Content

[0003] The technical content of the utility model is to provide a power control circuit which can linearly reduce the voltage in proportion when a generator is overloaded.

[0004] In order to solve the above problems, the utility model provides a power control circuit for linearly reducing the voltage of a generator in proportion to an overload, comprising an excitation voltage input terminal, the excitation voltage input terminal is connected to an excitation voltage rectifier unit, the excitation voltage rectifier unit is connected to a sampling voltage input potentiometer, the sampling voltage input potentiometer is connected to the negative input of a sampling voltage given control unit, the excitation voltage rectifier unit is connected to a motor excitation coil, the excitation voltage rectifier unit is connected to a reference voltage regulator tube through a current limiting resistor, the reference voltage regulator tube is connected to the positive input of the sampling voltage given control unit, and the sampling voltage rectifier unit is connected to the positive input of the sampling voltage given control unit. The output end of the voltage setting control unit is connected to the excitation current voltage control unit, the motor excitation coil is also connected to the excitation current voltage control unit, the excitation current voltage control unit is connected to the excitation current voltage sampling resistor, the output end of the current feedback setting control unit is connected to the excitation current voltage control unit, the excitation current voltage control unit is connected to the excitation current voltage sampling resistor through the excitation current sampling point, the excitation current voltage sampling resistor is connected to the positive input of the current feedback setting control unit, and the current feedback setting control unit is connected to the reference current voltage setting potentiometer.

[0005] As a further solution of the present invention, the current and voltage formed by the excitation current and voltage sampling resistor are compared with the given voltage of the reference voltage regulator tube and input into the current feedback given control unit. If it is greater than the given value, the excitation current decreases, otherwise it increases, and the excitation current also maintains the output power unchanged.

[0006] As a further solution of the utility model, the sampling voltage setting control unit and the current feedback setting control unit are operational amplifiers, and the excitation current voltage control unit includes an excitation power control transistor Q1 and a transistor Q2. When the overall circuit is not overloaded, the transistor Q2 does not work, and the motor excitation coil and the excitation current voltage sampling resistor are connected through the excitation power control transistor Q1. When the circuit is overloaded, the excitation current voltage sampling resistor forms a voltage drop and is input to the positive input end of the current feedback setting control unit and compared with the given voltage. When the voltage is greater than the given voltage, the output end of the current feedback setting control unit becomes a high level state and is input to the base input end of the transistor Q2. At this time, the base potential of the transistor Q1 is reduced and cut off, and the excitation current of the transistor Q1 disappears. At this time, there is no voltage on the excitation current voltage sampling resistor, and the circuit overload ends.

[0007] Compared with the related art, the power control circuit for linearly reducing the voltage of a generator in proportion to an overload provided by the utility model has the following beneficial effects:

[0008] 1. The utility model compares the current and voltage formed by the excitation current and voltage sampling resistor with the given voltage of the reference voltage regulator tube and inputs them into the current feedback given control unit. If the current and voltage are greater than the given voltage, the excitation current decreases, otherwise it increases. The excitation current also maintains the output power unchanged, thereby stabilizing the working state of the generator without overload.

[0009] 2. The utility model makes the sampling voltage of the sampling voltage input potentiometer come from the excitation, so that the device does not need to add a sampling voltage coil winding. The cancellation of the sampling voltage coil can effectively eliminate the risk of increased generator output voltage caused by poor contact or disconnection of the connector. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to facilitate understanding by those skilled in the art, the present invention is further described below in conjunction with the accompanying drawings.

[0011] Figure 1 This is a circuit structure diagram of a power control circuit that linearly reduces the voltage in proportion to an overloaded generator according to the utility model;

[0012] Figure 2 The utility model is a schematic diagram of linear voltage-power proportional reduction of a power control circuit for linearly reducing voltage in proportion to an overload of a generator.

[0013] In the figure: 1. Excitation voltage input terminal; 2. Excitation voltage rectification unit; 3. Sampling voltage input potentiometer; 4. Sampling voltage setting control unit; 5. Motor excitation coil; 6. Current limiting resistor; 7. Reference voltage regulator tube; 8. Excitation current and voltage control unit; 9. Current feedback setting control unit; 10. Excitation current and voltage sampling resistor; 11. Reference current and voltage setting potentiometer. DETAILED DESCRIPTION

[0014] Please refer to Figure 1-2 A power control circuit for linearly reducing the voltage of a generator in proportion to an overload includes an excitation voltage input terminal 1, the excitation voltage input terminal 1 is connected to an excitation voltage rectifier unit 2, the excitation voltage rectifier unit 2 is connected to a sampling voltage input potentiometer 3, the sampling voltage input potentiometer 3 is connected to the negative input of a sampling voltage given control unit 4, and then compared with the positive input terminal, and a low level is output when it is greater than the positive terminal, and then the output terminal is sent to an excitation current voltage control unit 8 for excitation control, the excitation voltage rectifier unit 2 is connected to a motor excitation coil 5, the excitation voltage rectifier unit 2 is connected to a reference voltage regulator tube 7 through a current limiting resistor 6, and the reference voltage regulator tube 7 and the sampling voltage given control unit 4 are connected to each other. The positive input of element 4 is connected, the output end of the sampling voltage setting control unit 4 is connected to the excitation current voltage control unit 8, the motor excitation coil 5 is also connected to the excitation current voltage control unit 8, the excitation current voltage control unit 8 is connected to the excitation current voltage sampling resistor 10, the output end of the current feedback setting control unit 9 is connected to the excitation current voltage control unit 8, the excitation current voltage control unit 8 is connected to the excitation current voltage sampling resistor 10 through the excitation current sampling point, the excitation current voltage sampling resistor 10 is connected to the positive input of the current feedback setting control unit 9, and the current feedback setting control unit 9 is connected to the reference current voltage setting potentiometer 11.

[0015] Preferably, the current voltage formed by the excitation current voltage sampling resistor 10 is compared with the given voltage of the reference voltage regulator tube 7 and input to the current feedback given control unit 9. If it is greater than the given voltage, the excitation current decreases, otherwise it increases, and the excitation current also maintains the output power unchanged. The sampling voltage of the sampling voltage input potentiometer 3 comes from the excitation, so that the device does not need to add a sampling voltage coil winding. The cancellation of the sampling voltage coil can effectively eliminate the risk of the generator output voltage increasing due to poor contact or disconnection of the connector;

[0016] Preferably, the sampling voltage setting control unit 4 and the current feedback setting control unit 9 are operational amplifiers, and the excitation current and voltage control unit 8 includes an excitation power control transistor Q1 and a transistor Q2. When the overall circuit is not overloaded, the transistor Q2 does not work, and the motor excitation coil 5 and the excitation current and voltage sampling resistor 10 are connected through the excitation power control transistor Q1. When the circuit is overloaded, the excitation current and voltage sampling resistor 10 forms a voltage drop and is input to the positive input end of the current feedback setting control unit 9 and compared with the given voltage. When it is greater than the given voltage, the output end of the current feedback setting control unit 9 becomes a high level state and is input to the base input end of the transistor Q2. At this time, the base potential of the transistor Q1 is reduced and cut off. At this time, the excitation current of the transistor Q1 disappears. At this time, there is no voltage on the excitation current and voltage sampling resistor 10, and the circuit overload ends.

[0017] Example 1: Please refer to Figure 2 , a rated power of 8 kW generator output voltage 230 volts, with 8 kW rated load, the rated voltage of the generator is 230 volts, when we need to overload 1 kW, the actual power is 9 kW load, the generator detects that the excitation current is larger than the previous excitation current, the constant power controller will automatically adjust the output voltage 230 volts voltage will drop linearly in proportion, the experimental data is about 220 volts, and so on, continue to increase the power load, the output voltage is the original 220 volts, about to drop to 200 volts, if continue to load, the voltage continues to drop, according to the curve graph experimental data show that when the load is added to more than 40% the voltage drops to about 180 volts, the curve graph is shown in the figure,

[0018] It can be designed as an adjustable coil welding machine current. By changing the excitation current using a constant power controller, the coil current of the generator welding machine can be changed to output the required current. The power is stable and the fuel is fully burned, which saves energy and reduces pollution.

[0019] Working principle: Constant voltage source, referred to as stabilized voltage (AVR) voltage sampling comes from the sampling voltage input potentiometer 3 of the excitation voltage rectifier unit 2. When the sampling voltage increases, the output terminal P1 of the sampling voltage setting control unit 4 will appear low level, and the transistor control terminal of the excitation voltage and current control unit is low level, then the transistor Q1 is cut off, and the motor excitation coil 5 has no current, then the voltage drops.

[0020] Constant current source, referred to as stable current, constant current (ACP) is constant power. The principle is that when the power increases, the current of transistor Q1 increases, and the excitation current voltage sampling resistor 10 connected in series to the emitter of transistor Q1 forms a voltage drop, and a voltage drop voltage is formed at the voltage drop point. The greater the current, the greater the voltage drop value. The voltage is fed back to the positive end of the current feedback given control unit 9, and the control end outputs a high level to the base of the transistor Q2 of the excitation current voltage control unit 8, then the base of Q1 is a low level, Q1 is cut off, the excitation coil has no current, the generator voltage drops, and the power drops. Set the reference voltage, the current is set, and the output power is stable.

[0021] The standard parts used in this embodiment can be purchased directly from the market and can be customized according to the description in the specification and drawings. The specific connection methods of each part adopt conventional means such as mature electronic accessories bolts, rivets, welding, etc. in the prior art. The electronic accessories machinery, parts and equipment all adopt conventional models in the prior art, and the components known to technical personnel in this field, their structures and principles can be known to technical personnel through technical manuals or through conventional experimental methods.

[0022] Although the embodiments of the present invention have been shown and described, it is understood by those skilled in the art that various changes, modifications, substitutions and variations or direct or indirect applications may be made to these embodiments without departing from the principles and spirit of the present invention. In other related technical fields, the scope of the present invention is defined by the attached claims and their equivalents, which are equally included in the scope of patent protection of the present invention.

Claims

1. A power control circuit for linearly reducing the voltage of a generator in proportion to an overload, comprising an excitation voltage input terminal (1), characterized in that: The excitation voltage input terminal (1) is connected to an excitation voltage rectifier unit (2), the excitation voltage rectifier unit (2) is connected to a sampling voltage input potentiometer (3), the sampling voltage input potentiometer (3) is connected to a negative input of a sampling voltage setting control unit (4), the excitation voltage rectifier unit (2) is connected to a motor excitation coil (5), the excitation voltage rectifier unit (2) is connected to a reference voltage regulator tube (7) via a current limiting resistor (6), the reference voltage regulator tube (7) is connected to a positive input of a sampling voltage setting control unit (4), the output terminal of the sampling voltage setting control unit (4) is connected to an excitation current voltage control unit (8) ), the motor excitation coil (5) is also connected to the excitation current voltage control unit (8), the excitation current voltage control unit (8) is connected to the excitation current voltage sampling resistor (10), the output end of the current feedback setting control unit (9) is connected to the excitation current voltage control unit (8), the excitation current voltage control unit (8) is connected to the excitation current voltage sampling resistor (10) through the excitation current sampling point, the excitation current voltage sampling resistor (10) is connected to the positive input of the current feedback setting control unit (9), and the current feedback setting control unit (9) is connected to the reference current voltage setting potentiometer (11).

2. A power control circuit for linearly decreasing the voltage in proportion to an overload of a generator according to claim 1, characterized in that: The current and voltage formed by the excitation current and voltage sampling resistor (10) are compared with the given voltage of the reference voltage regulator tube (7) and input to the current feedback given control unit (9). If the current and voltage are greater than the given voltage, the excitation current decreases, otherwise it increases, and the excitation current also maintains the output power unchanged.

3. A power control circuit for linearly decreasing the voltage in proportion to an overload of a generator according to claim 1, characterized in that: The sampling voltage setting control unit (4) and the current feedback setting control unit (9) are operational amplifiers. The excitation current voltage control unit (8) includes an excitation power control transistor Q1 and a transistor Q2. When the overall circuit is not overloaded, the transistor Q2 does not work. The motor excitation coil (5) and the excitation current voltage sampling resistor (10) are connected via the excitation power control transistor Q1. When the circuit is overloaded, the excitation current voltage sampling resistor (10) forms a voltage drop and is input to the positive input end of the current feedback setting control unit (9) and compared with a given voltage. When the voltage is greater than the given voltage, the output end of the current feedback setting control unit (9) changes to a high level state and is input to the base input end of the transistor Q2. At this time, the base potential of the transistor Q1 decreases and is cut off. At this time, the excitation current of the transistor Q1 disappears. At this time, there is no voltage on the excitation current voltage sampling resistor (10), and the circuit overload ends.

Images