CN105656319A

CN105656319A - Inverter controller based on measurement and control of power factors of output circuit

Info

Publication number: CN105656319A
Application number: CN201610079795.9A
Authority: CN
Inventors: 孔祥伟
Original assignee: Zhejiang Rayak Electronics Co Ltd
Current assignee: Zhejiang Rayak Electronics Co Ltd
Priority date: 2016-02-04
Filing date: 2016-02-04
Publication date: 2016-06-08

Abstract

The invention relates to an inverter controller based on measurement and control of power factors of an output circuit. The inverter controller mainly comprises a rectifier bridge connected with a three-phase winding of a three-phase permanent magnet generator, a direct-current filtering circuit, an inverter circuit, a direct-current voltage detection circuit, a direct-current current detection circuit, an alternating-current voltage detection circuit, an alternating-current current detection circuit, an alternating-current phase standard signal generation circuit, an alternating-current phase detection circuit, an IGBT (Insulated Gate Bipolar Translator) triggering unit circuit and a control part. When the generator is connected with a load control part, the control part can be used for circularly detecting values of direct-current voltage, direct-current current, alternating-current voltage and alternating-current current of a power circuit; under the matching of the alternating-current phase standard signal generation circuit, the alternating-current phase detection circuit and a load character judging part in the control part, the power factors of the load and characters of the load are rapidly calculated, so that output voltage of the system is regulated by changing pulse width of the IGBT triggering unit, and furthermore, the suitable power factors of the output circuit are acquired.

Description

A kind of inverter controller based on output circuit power factor observing and controlling

Technical field

The present invention relates to a kind of inverter controller based on output circuit power factor observing and controlling; it is especially used in generating set; load for generating set dragging has identification function and the phase angle according to the voltage of load, electric current regulates the external output voltage of unit and power, to realize energy-conservation and to controller protection.

Background technology

The small power generation unit dragged by miniature gasoline engine or small diesel engine in recent years use in daily life and field work is more and more extensive, the consciousness of environmental protection and energy saving simultaneously is also increasingly deep into the consumption consciousness of people, so small power generation unit is also required to adapt to this kind of trend.

Occupation mode according to small power generation unit, gasoline engine generator is often taken as the independent current source of movable type and uses, and is mainly made up of gasoline engine, synchronous alternator and controller. The three-phase alternating current frequency that in design, gasoline engine used sends is 350��640Hz, voltage is 300��550V, DC high voltage is become by three-phase commutation bridge, it is then passed through blood pressure lowering link (buck converter) and is down to about 350V, become the alternating current of 220V/50Hz etc. for load finally by inversion link with LC filter transform. The load of small generator includes a kind of main load equipment that the small-sized ac motors such as small-sized alternating current generator, luminaire, electric furnace are above-mentioned generating sets. Ac motor due under different loading conditions its power factor closely not identical yet, designing requirement according to ac motor is in general when its output its power factor when nominal load is the highest, if motor load rate can be detected and regulates the terminal voltage of motor as requested, the Energy Saving Control of motor can be realized, in the running of generating set drive motor, along with the load of motor changes, its efficiency and power also will change, particularly when underloading, both will become very low. Additionally the control object of soft initiator is common AC asynchronous motor, the input voltage of motor can be controlled by it, and the light-load energy saving of motor is run and is generally also required to be realized by the input voltage of adjustment motor, so for the permanent-magnet synchronous AC generator group with inverter circuit, the soft start to motor can be realized simultaneously and regulate by regulating the terminal voltage of motor itself, it is achieved the motor energy-saving run when underloading.

Summary of the invention

For solving problem above; it is an object of the invention to provide a kind of controller; the power circuit of controller is connected with main circuit and the control circuit of the magneto alternator of generating set; rectified three-phase circuit and controlled inverter circuit is utilized to meet generating set to the energy-conservation instructions for use of unequally loaded; alternating current generator can be carried out soft start simultaneously, and inverter circuit is carried out safeguard protection.

In order to meet above-mentioned requirements and purpose, the present invention provides a kind of inverter controller based on output circuit power factor observing and controlling, and described inverter controller possesses such as lower component and circuit:

Rectifier bridge, DC filtering circuit, ac filter circuit, inverter circuit, DC voltage testing circuit, D.C. current detecting circuit, ac voltage detection circuit, alternating current testing circuit, AC phases reference signal generative circuit, AC current phase testing circuit, IGBT trigger element circuit and the control portion being connected with the three-phase windings of three-phase permanent magnet electricity generator;

Wherein, described DC voltage testing circuit, D.C. current detecting circuit, ac voltage detection circuit, alternating current testing circuit, AC phases reference signal generative circuit, AC current phase testing circuit, IGBT trigger element circuit are all connected with control portion;

Described rectifier bridge, DC filtering circuit, DC voltage testing circuit, D.C. current detecting circuit connect the input of described inverter circuit, described ac filter circuit, ac voltage detection circuit, alternating current testing circuit, AC phases reference signal generative circuit, AC current phase testing circuit connect the outfan of described inverter circuit, and described IGBT trigger element circuit connects the control end of described inverter circuit.

Further, according to inverter controller as above, described control portion has the fundamental voltage setup unit that can regulate inverter circuit output voltage values, the power compensating unit of DC circuit power measurement, phase angle adjustment unit, and may determine that the load characteristic judging part of load characteristic;

When inverter controller load changes, the voltage of alternating current power supply of inverter circuit output, electric current and phase value detect by each testing circuit above-mentioned in described control portion and the pulse that triggers according to corresponding logic control inverter circuit changes the phase angle of alternating current, to realize the above-mentioned load Energy Saving Control when underloading.

Further, according to inverter controller as above, can line disconnection when above-mentioned load exceedes system load.

Further, according to inverter controller as above, if the power-factor angle of load is too small, cut off the output of IGBT trigger element circuit by above-mentioned described line disconnection.

Further, according to inverter controller as above, when the character of load is perception or capacitive, the output voltage reducing inverter circuit realizes reduced-voltage starting hence for load.

Further, it is adjustable according to inverter controller as above, the output voltage of described inverter circuit and the target phase angles of electric current.

Further, according to inverter controller as above, the output voltage values of described inverter circuit is adjustable.

Further, according to inverter controller as above, inverter controller arranges a switch controlling start and stop, and at least one is for the instruction device of duty instruction.

Further, according to inverter controller as above, described instruction device is LED.

Further, according to inverter controller as above, according to the power of output and the difference of apparent energy and bearing power, described control portion judges whether system is operated in the mode of resistive load;

If so, then turn to resistive load working method, now change the triggering pwm value of IGBT and do not change moment of its triggering, and the output of the size adjustment system according to bearing power; The duty of cutting system when load is beyond the ability to work of system simultaneously;

As no, then system is carrying out next step mode judging whether to be in capacitive load, the mode judged is the saltus step that system waits reference voltage signal, when system detects that the voltage phase signal of this signal positive transition then horse back reading alternating current circuit reads the current phase signal of alternating current circuit simultaneously, judge the load characteristic of system according to the value of the two.

The invention provides a kind of controller architecture adopting high performance single-chip microcomputer device to control, it has following function:

1, the electromotor of small power generation unit is controlled.

2, to the detection of the power factor of the motor that above-mentioned unit drives, adjustment, change according to motor load, regulating the input voltage of motor in real time, the power factor then keeping motor is constant, it is achieved the light-load energy saving of motor.

3, the requirement such as soft start of the motor that above-mentioned unit is driven is met.

4, additionally also there is the ability that the inverter circuit in the control of electromotor provides protection.

Accompanying drawing explanation

Fig. 1 is the connection line figure of the controller of an embodiment of the invention;

Fig. 2 is the logic diagram of the main control circuit of the present invention;

Fig. 3 is the logical judgment figure of the load characteristic of the present invention;

Fig. 4 is the logical judgment figure for system overcharge protection of the present invention;

Fig. 5 is the logic diagram that the load to low power factor of the present invention carries out input voltage adjustment.

Fig. 6 is the measuring circuit figure of DC voltage;

Fig. 7 is the measuring circuit figure of DC current;

Fig. 8 is the measuring circuit figure of alternating current;

Fig. 9 is the measuring circuit figure of alternating voltage;

Figure 10 is the measuring circuit figure of AC current phase;

Figure 11 is the phase measuring circuit figure of alternating voltage;

Figure 12 is the triggering generative circuit figure of inversion unit.

Detailed description of the invention

Below in conjunction with drawings and Examples, the present invention is described in detail.

It is an object of the invention to provide a kind of controller; the power circuit of controller is connected with main circuit and the control circuit of the magneto alternator of generating set; rectified three-phase circuit and controlled inverter circuit is utilized to meet generating set to the energy-conservation instructions for use of unequally loaded; alternating current generator can be carried out soft start simultaneously, and inverter circuit is carried out safeguard protection.

Fig. 1 is the primary structure figure of a kind of detailed description of the invention of the present invention, in figure 1 is as the rotor machine in the controlled parts of the present invention, it be a kind of electromotor dragged by electromotor or other can carry out the power supply of alternative electric generation, we determined that it is the rotor machine dragged by electromotor with reference to this example.

Electromotor has two groups or more coil, one group as electromotor to the main power source of externally fed, one group of control power supply as the present invention, the main power circuit of electromotor is connected with the three-phase commutation bridge of control, electric current arranges the filtering of capacitance group network 3 and electric current is carried out smothing filtering through the left side of rectifier bridge 2, and the electric current rear positive pole of its direct current after filtering is connected with the positive pole of the H-bridge inverter circuit being positioned at behind.

Configure inductance in the left side of H inverter bridge and the alternating current after inversion is carried out smothing filtering by capacitance group network 6, the incoming end of this electric current connection system load afterwards.

At the sample circuit of DC voltage disposed behind of three-phase commutation bridge with configure a diverter 8 on DC loop, being used for detecting the voltage and current signal of DC circuit is Ud and Id respectively, and these two signals are fed to the control port of controller.

Main control part at controller has the triggering line that can trigger H bridge IGBT, and its output signal is G1-G4.

Being configured with the current sampling circuit 5 of ac current measurement between inductance on H inverter circuit and ac circuit, its sampled signal Ia is fed to the control port of controller.

Arranging the sample circuit of alternating voltage in the left side of inductance 9-0 and 9-1, and configure a diverter 7 on ac circuit, the voltage and current phase signal being used for detecting alternating current circuit is Ua and IPh respectively, and these two signals are fed to the control port of controller.

Having the voltage-phase testing circuit 11 for detecting alternating voltage phase on ac circuit, the signal of its detection is sent into and is controlled port simultaneously.

Control circuit arranges a switch controlling system start and stop, and at least one is for the instruction device of working state of system instruction, such as LED.

If the power generating source that system controlled device is electromotor drawing generator, then also should configure the igniter of at least one electromotor (gasoline engine) in the controls.

As in figure 2 it is shown, provide a kind of inverter controller based on output circuit power factor observing and controlling to meet above-mentioned requirements and the purpose present invention, described inverter controller possesses such as lower component and circuit:

Wherein, described control portion has the fundamental voltage setup unit that can regulate inverter circuit output voltage values, the power compensating unit of DC circuit power measurement, phase angle adjustment unit, and may determine that the load characteristic judging part of load characteristic;

Wherein, can line disconnection when above-mentioned load exceedes system load.

Wherein, if the power-factor angle of load is too small, cut off the output of IGB trigger element circuit by above-mentioned described line disconnection.

Wherein, when the character of load is perception or capacitive, the output voltage reducing inverter circuit realizes reduced-voltage starting hence for load.

Wherein, the output voltage of described inverter circuit and the target phase angles of electric current are adjustable.

Wherein, the output voltage values of described inverter circuit is adjustable.

Fig. 3, Fig. 4, Fig. 5 are that system is to the judgement flow process of load characteristic and corresponding treatment measures. It is understood that substantially can be divided into following three classes for electricity consumption device:

Inductive load: daylight lamp, motor, electric refrigerator, refrigerator-freezer, electric fan, transformator, air-conditioner etc.

Capacitive load: television set, host computer, display, scialyscope, all power supply units etc. converted with Switching Power Supply.

Resistive load: electric light big gun, electric cautery, hair-dryer and all electrical appliances with heating wire for heating.

First the electric parameter of diagram is measured upon power-up of the system so that it is determined that system enters that duty (Fig. 3):

1, according to the power of output and the difference of apparent energy and bearing power, system judges whether system is operated in the mode of resistive load. If so, then turning to resistive load working method, now system has only to the stability of regulated output voltage, is the moment changing the triggering pwm value of IGBT and not changing its triggering specifically, and the output of the size adjustment system according to bearing power. The duty (Fig. 3) of cutting system when load is beyond the ability to work of system simultaneously.

2, as no, then system is carrying out next step mode judging whether to be in capacitive load, the mode judged is the saltus step that system waits reference voltage signal, when system detects that this signal positive transition is then read GPh1 and read IPh at once simultaneously, judges the load characteristic of system according to the value of the two.

The load of the motor for inductive load etc, its principle is exactly detect the power factor of motor, controls the input voltage of motor by controlling the silicon controlled angle of flow. Its result is the reactive power that can save motor, reduces its iron loss, copper loss and line loss. And for the load of actuating motor etc, corresponding measure can also be set by each above detected value and realize the reduced-voltage starting of motor to realize the smooth startup of motor. The duty (Fig. 4) of cutting system when load is beyond the ability to work of system simultaneously.

Additionally motor is under non-rated voltage and non-rated frequency, its loss is greatly increased, motor is made to be in unreasonable running status, motor performance is caused notable change by the change outside supply voltage and frequency allowed band, especially when supply frequency reduction, voltage increase, motor no-load loss and no-load current significantly to rise, and make power factor reduce. When voltage reduces, motor speed declines, and makes copper loss of rotor increase, causes that power factor reduces. So now system can pass through the measurement to motor power factor, the power factor of load-side is made to stablize within certain scope to realize energy-conservation (Fig. 5) again through suitable adjustment.

Principle for the load regulation of capacitive is similar with above-mentioned method, is also the width of the trigger instants triggering pulse and pulse by changing the IGBT in the inverter coupling that realizes this example and load, repeats no more here.

Fig. 6 is the measuring circuit part of the DC voltage in Fig. 2, and DC voltage is carried out dividing potential drop by R23 and R34 by it, and the clamper through BAT54S obtains the sampled signal U_DC of main circuit voltage, is sent to the respective pins of single-chip microcomputer.

Fig. 7 is the measuring circuit part of the DC current in Fig. 2, it is made up of an amplifier circuit, the positive inverting input of amplifier is connected across the two ends of diverter R706, to the signal through over-sampling through the conditioning of amplifier circuit, convert the signal that single-chip microcomputer may identify which to, be sent to the respective pins of single-chip microcomputer.

Fig. 8 is the measuring circuit part of the alternating current in Fig. 2, it is made up of Special electric current detection circuit, and the input of circuit is connected in major loop, through the signal of over-sampling through the conditioning of amplifier circuit, convert the signal that single-chip microcomputer may identify which to, be sent to the respective pins of single-chip microcomputer.

Fig. 9 is the measuring circuit part of the alternating voltage in Fig. 2, it is made up of Special electric current detection circuit, and the input of circuit is connected in major loop, through the signal of over-sampling through the conditioning of amplifier circuit, convert the signal that single-chip microcomputer may identify which to, be sent to the respective pins of single-chip microcomputer.

Figure 10 is the measuring circuit part of the AC current phase in Fig. 2, it is mainly made up of an amplifier circuit, a diverter and a Schmidt trigger circuit, the diverter of circuit is serially connected in major loop, through the signal of over-sampling through the conditioning of amplifier circuit, converted to square-wave pulse signal IPh by Schmidt trigger, be sent to the respective pins of single-chip microcomputer.

Figure 11 is the phase measuring circuit part of the alternating voltage in Fig. 2, it is formed bleeder circuit by R43 and R44, filtering through C40 is input in Schmidt trigger, the input divider resistance of circuit is connected in parallel in major loop, the square-wave pulse of Schmidt trigger output, is sent to the respective pins of single-chip microcomputer.

Single-chip microcomputer can compare the generation moment of two kinds of phase signals above, determines the phase time of alternating voltage and electric current. Thus may determine that the character of load. The phase contrast of alternating voltage and electric current can certainly be calculated with this, but this example does not so calculate, and is not discussed here.

Figure 12 is the triggering generative circuit of the inversion unit in this example. Adopt SPWM copped wave form, single-chip microcomputer in circuit produces sine wave by SPI mouth, it is input to special chip U402 through corresponding conversion, its triggering pulse that can produce to meet SPWM waveform, it is used for the IGBT triggering in inverter circuit, as long as so we could alter that the width triggering pulse above, it is possible to change the output voltage of inverter circuit.

The shutdown pin of the special chip in circuit connects the pin cpuSHUTDOWN of single-chip microcomputer, and it can directly close U402 when system needs, thus the external output power of cutting system.

According to the present invention, when controller noted above is arranged on generating set, operating and the work of the electromotor of generating set can be controlled, after engine start, the solar term throttle of electromotor can be regulated automatically, electromotor is made to be operated in suitable rotating speed, the controller noted above corresponding rectification circuit of control and inverter circuit export suitable industrial frequency AC electric power simultaneously, after generating set connects load, first controller noted above detects the character of load and the phase angle of alternating voltage and electric current, data according to obtaining determine it is which kind of load, if phase angle electric current and voltage such as being detected is 0.2, and alternating current is relatively big and phase place of electric current simultaneously lags behind voltage, it may determine that be a motor type equipment for load, control system will attempt reducing the output voltage of inverter circuit, to reach the power factor set.

If additionally when the moment that load accesses, controller finds that now electric current is bigger, the voltage (output voltage set of comparing) simultaneously exported is relatively low, controller just can be attempted reducing output voltage and this kind equipment is carried out reduced-voltage starting, when along with when constantly raising particular up to setting voltage value of output voltage, just can search for a suitable magnitude of voltage around this voltage to attempt, see that the power-factor of load now is if appropriate for the scope determined.

According to present disclosure, the DC link that controller has main circuit and the testing circuit exchanging link, first the control portion of controller can block the output of inverter circuit after the power-up, then the voltage of the DC link of rectification circuit is detected, when being not detected by the requirement that the voltage of DC link of rectification circuit reaches default, inversion link will not be opened.

According to present disclosure, controller can when being connected to the rated power that the power of load of generating set exceedes generating set, the parts that control of controller can the output of inverter circuit in cutting-off controlling device actively, corresponding sound and light alarm can be exported simultaneously, reduce the rotating speed of electromotor in generating set simultaneously, to avoid the generation of the phenomenons such as engine mounted longitudinally racing.

According to present disclosure, controller has the voltage and current of the directly alternating current of detection controller output, when the phase angle of said two devices is excessive and cosine is only small, the ratio that the available power of at this moment system output accounts for apparent energy is little, the reactive power of the load of controller accounts for relatively larger, so load current at this moment is also relatively larger, because the partition electric current of the rectifier bridge of controller cannot reversely flow back to the synchronous motor of system, the power that this part reactive current is carried can only consume in the inductance and electric capacity of controller, cause the heating of controller, the Converting Unit of controller even can be burnt when reactive current is excessive, so the present invention is provided with the control circuit from the control portion of controller to its inverter circuit, when control portion detects that above-mentioned big current conditions can turn off the line disconnection of controller inverter circuit automatically when occurring, thus can be effectively protected the safety of controller.

This example has briefly introduced a kind of occupation mode and the operating circuit of the present invention, and it can be widely used in small-sized electrical generator fields, but is also not necessarily limited to this.

Obviously, the present invention can be carried out various change and modification without deviating from the spirit and scope of the present invention by those skilled in the art. So, if these amendments and modification to the present invention belong within the scope of the claims in the present invention and equivalent technology thereof, then the present invention is also intended to comprise these and changes and modification.

Claims

1. the inverter controller based on output circuit power factor observing and controlling, it is characterised in that:

Described inverter controller possesses such as lower component and circuit:

2. inverter controller according to claim 1, it is characterised in that:

Described control portion has the fundamental voltage setup unit that can regulate inverter circuit output voltage values, for the power compensating unit of DC circuit power measurement, phase angle adjustment unit, and may determine that the load characteristic judging part of load characteristic;

When the load of inverter controller changes, the voltage of alternating current power supply of inverter circuit output, electric current and phase value detect by each testing circuit above-mentioned in described control portion and the pulse that triggers according to corresponding logic control inverter circuit changes the phase angle of alternating current, to realize the above-mentioned load Energy Saving Control when underloading.

3. inverter controller according to claim 1, it is characterised in that: can line disconnection when above-mentioned load exceedes system maximum load.

4. inverter controller according to claim 3, it is characterised in that: if the power-factor angle of load is too small, cut off the output of described IGBT trigger element circuit by above-mentioned described line disconnection.

5. inverter controller according to claim 1, it is characterised in that: when the character of load is perception or capacitive, the output voltage reducing inverter circuit realizes reduced-voltage starting hence for load.

6. inverter controller according to claim 4, it is characterised in that: the output voltage of described inverter circuit and the target phase angles of electric current are adjustable.

7. inverter controller according to claim 5, it is characterised in that: the output voltage values of described inverter circuit is adjustable.

8. inverter controller according to claim 1, it is characterised in that: a switch controlling start and stop is set in inverter controller, and at least one is for the instruction device of duty instruction.

9. inverter controller according to claim 8, it is characterised in that:

Described instruction device is LED.

10. inverter controller according to claim 1, it is characterised in that:

According to the power of output and the difference of apparent energy and bearing power, described control portion judges whether system is operated in the mode of resistive load;