CN102480243A - Direct current component control method and system used for three-phase or single-phase inverter - Google Patents

Abstract

The invention proposes a DC component control method and system for a three-phase or single-phase inverter. Wherein, the method for the three-phase inverter includes: detecting the output voltage of the three-phase inverter and its DC component; converting the DC component from a stationary coordinate to a rotating coordinate to obtain a component of the DC component above the rotating coordinate; Calculate the DC voltage adjustment value according to the component of the DC component above the rotating coordinate and the DC voltage reference value; calculate the voltage reference value according to the DC voltage adjustment value and the reference output voltage; calculate the voltage reference value according to the voltage reference value and the output of the three-phase inverter Voltage calculation of the output adjustment voltage of the three-phase inverter; the conversion of the output adjustment voltage of the three-phase inverter from the rotating coordinate to the stationary coordinate and PWM modulation to obtain the driving signal of the three-phase inverter; and according to the driving signal to A three-phase inverter is used for drive control. The invention can effectively reduce the direct current component in the output voltage of the inverter, so as to meet the requirement of the load.

Description

DC component control method and system for three-phase or single-phase inverter

technical field

The invention relates to the technical field of electrical manufacturing, in particular to a DC component control method and system for three-phase or single-phase inverters.

Background technique

Sine wave inverters are widely used in uninterruptible power supply (UPS), frequency converters and other fields, and the types of loads carried are becoming more and more diverse. This requires that the output of the inverter should be a pure sine wave and should not contain DC components and other components. During the research and practice of the prior art, the inventor found that the DC component of the inverter is unavoidable due to reasons such as BUS voltage imbalance, inaccurate sampling, and deviation of circuit parameters. If effective measures are not taken to suppress it, the DC component in the output voltage may cause harm to the loads it supplies, such as inductive loads such as "magnetic saturation" of transformers, etc., so that the loads cannot work normally. Therefore, how to eliminate the DC component in the output voltage has become an urgent problem to be solved.

Contents of the invention

The purpose of the present invention is to solve at least one of the above-mentioned technical defects, especially the defect that the DC component in the output voltage cannot be eliminated in the prior art.

In order to achieve the above object, the present invention proposes a DC component control method for a three-phase inverter, comprising the following steps: detecting the output voltage of the three-phase inverter and the DC component of the output voltage; The DC component of the output voltage is converted from stationary coordinates to rotating coordinates to obtain a component of the DC component above the rotating coordinate; according to the component of the DC component above the rotating coordinate and the DC voltage given value to calculate the DC voltage adjustment value; according to the DC voltage adjustment value and the reference output voltage of the three-phase inverter to calculate the voltage given value of the three-phase inverter; according to the voltage given value and the The output voltage of the three-phase inverter is calculated to adjust the output voltage of the three-phase inverter; the output adjustment voltage of the three-phase inverter is converted from the rotating coordinate to the static coordinate and pulse width modulation is performed. PWM modulation to obtain a driving signal of the three-phase inverter; and performing driving control on the three-phase inverter according to the driving signal of the three-phase inverter.

Another aspect of the present invention also proposes a DC component control system for a three-phase inverter, including: a three-phase inverter; a detection module for detecting the output voltage of the three-phase inverter and the A DC component of the output voltage; a controller, configured to convert the DC component of the output voltage from a stationary coordinate to a rotating coordinate to obtain a component of the DC component above the rotating coordinate, and according to the DC component in calculating a DC voltage adjustment value based on the components on the rotating coordinates and a given DC voltage value, and calculating the voltage of the three-phase inverter according to the DC voltage adjustment value and the reference output voltage of the three-phase inverter a given value, and calculate the output adjustment voltage of the three-phase inverter according to the voltage reference value and the output voltage of the three-phase inverter, and perform the output adjustment voltage on the three-phase inverter Converting the rotating coordinates to the stationary coordinates and performing pulse width modulation (PWM) modulation to obtain a driving signal of the three-phase inverter; and a driving module, used for obtaining the three-phase inverter according to the controller The driving signal performs driving control on the three-phase inverter.

Another aspect of the present invention also proposes a DC component control method for a single-phase inverter, including the following steps: constructing a three-phase inverter structure according to the structure of the single-phase inverter, and The single-phase inverter is used as the first phase of the three-phase inverter; the output voltage of the single-phase inverter and the DC component of the output voltage are detected, and used as the first phase of the first phase An output voltage and the first DC component of the first output voltage; calculating the first DC component of the three-phase inverter according to the structure of the three-phase inverter and the first output voltage of the first phase The second output voltage of the two phases, and the third output voltage of the third phase, and the second DC component of the second output voltage and the third DC component of the third output voltage are set to zero; for the first The direct current component, the second direct current component and the third direct current component perform the conversion from the stationary coordinate to the rotating coordinate to obtain the components of the first direct current component, the second direct current component and the third direct current component above the rotating coordinate; According to the components of the first DC component, the second DC component and the third DC component above the rotating coordinates and the first DC voltage given value of the first phase, the second DC voltage of the second phase The DC voltage given value and the third DC voltage given value of the third phase calculate the first DC voltage adjustment value of the first phase, the second DC voltage adjustment value of the second phase and the third The third DC voltage adjustment value of the phase; according to the first DC voltage adjustment value, the second DC voltage adjustment value and the third DC voltage adjustment value, and the first reference output voltage of the three-phase inverter, the second calculating a first given voltage value of the first phase, a second given voltage value of the second phase, and a third given voltage value of the third phase with reference to the output voltage and a third reference output voltage; According to the first given voltage value, the second given voltage value and the third given voltage value, as well as the first output voltage, the second output voltage and the third output voltage, the first voltage of the first phase is calculated. Output the regulated voltage, the second output regulated voltage of the second phase, and the third output regulated voltage of the third phase; perform the said first output regulated voltage, the second output regulated voltage and the third output regulated voltage converting the rotating coordinates to the stationary coordinates and performing PWM modulation to obtain the first driving signal of the first phase, the second driving signal of the second phase and the third driving signal of the third phase; and Driving and controlling the single-phase inverter according to the first driving signal.

Another aspect of the present invention also proposes a DC component control system for a single-phase inverter, including: a single-phase inverter; a detection module for detecting the output voltage of the single-phase inverter and the a DC component of the output voltage; a controller configured to perform the function of preserving a structure of a three-phase inverter configured according to the structure of the single-phase inverter, wherein the single-phase inverter is the first phase in the three-phase inverter; used to use the output voltage of the single-phase inverter detected by the detection module and the DC component of the output voltage as the first output voltage of the first phase and the first DC component of the first output voltage, and calculate the second phase of the three-phase inverter according to the structure of the three-phase inverter of the construction and the first output voltage of the first phase The second output voltage of the second output voltage, and the third output voltage of the third phase, and the second DC component of the second output voltage and the third DC component of the third output voltage are set to zero; for the first converting the DC component, the second DC component, and the third DC component from stationary coordinates to rotating coordinates to obtain components of the first DC component, the second DC component, and the third DC component above the rotating coordinates, And according to the components of the first DC component, the second DC component and the third DC component above the rotating coordinates and the first DC voltage given value of the first phase, the second DC voltage of the second phase The first DC voltage adjustment value of the first phase is calculated by two DC voltage given values and the third DC voltage given value of the third phase, and the second DC voltage adjustment value of the second phase and the first DC voltage adjustment value of the second phase are calculated. The third DC voltage adjustment value of the three phases; used for adjusting the first DC voltage value, the second DC voltage adjustment value and the third DC voltage adjustment value, and the first reference output voltage of the three-phase inverter , the second reference output voltage and the third reference output voltage respectively calculate the first voltage given value of the first phase, the second voltage given value of the second phase and the third voltage given value of the third phase Fixed value; used to calculate the first voltage given value, the second voltage given value and the third voltage given value, as well as the first output voltage, the second output voltage and the third output voltage The first output adjustment voltage of one phase, the second output adjustment voltage of the second phase, and the third output adjustment voltage of the third phase; used to adjust the first output adjustment voltage, the second output adjustment voltage and the The third output adjustment voltage converts the rotating coordinates to the stationary coordinates and performs PWM modulation to obtain the first driving signal of the first phase, the second driving signal of the second phase and the third phase a third driving signal; and a driving module, configured to drive and control the single-phase inverter according to the first driving signal.

The present invention controls the direct current component in the output voltage of the inverter through space vector control, thereby effectively reducing the direct current component in the output voltage of the inverter to meet the load requirement. Moreover, the DC component vector control of the present invention can be used in combination with the current space vector control mode, so it is simple and reliable without increasing the cost.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Description of drawings

The above and/or additional aspects and advantages of the present invention will become apparent and easy to understand from the following description of the embodiments in conjunction with the accompanying drawings, wherein:

FIG. 1 is a schematic diagram of a control method of an inverter in the prior art;

2 is a flowchart of a DC component control method for a three-phase inverter according to Embodiment 1 of the present invention;

3 is a schematic diagram of a second-order low-pass filter according to an embodiment of the present invention;

4 is a structural diagram of a DC component control system for a three-phase inverter according to Embodiment 1 of the present invention;

5 is a structural diagram of a controller according to Embodiment 1 of the present invention;

6 is a flowchart of a DC component control method for a single-phase inverter according to Embodiment 2 of the present invention;

Fig. 7 is the topological circuit structure of the half-bridge three-phase inverter constructed in Embodiment 2 of the present invention;

FIG. 8 is a structural diagram of a DC component control system for a single-phase inverter according to Embodiment 2 of the present invention;

FIG. 9 is a structural diagram of a controller according to Embodiment 2 of the present invention.

Detailed ways

Embodiments of the present invention are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals designate the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary only for explaining the present invention and should not be construed as limiting the present invention.

The DC component vector control method of the present invention can be combined with the existing vector control method. In order to have a clear understanding of the present invention, the following briefly introduces the existing vector control method. Space vector technology has the advantages of high voltage stabilization accuracy and good dynamic response performance, and it can transform its own power relationship in the d/q/0 rotating coordinate system. Therefore, its own voltage and current are no longer sinusoidal AC quantities in reality, but DC components in the rotating coordinate system. The controller generally adopts a double-loop control structure with an inner current loop and an outer voltage loop. The voltage and current are both DC components in the rotating coordinate system obtained after transformation. The structure is shown in Figure 1. But in some other ways, only the voltage loop is included, and the current loop is not included. The present invention can be combined with both modes. The output voltage Ua, Ub, Uc and the inductor current Ia, Ib, Ic are transformed by the d/q/0 rotating coordinate system to obtain the d-axis, q-axis, and 0-axis components of the voltage and current, and use them as the voltage loop and current respectively The control object of the ring.

In addition, in the embodiments of the present invention, the DC component control method of the present invention can be applied not only to three-phase inverters, but also to single-phase inverters. If it is applied in a single-phase inverter, a virtual three-phase inverter needs to be constructed based on the single-phase inverter, which will be described in detail in subsequent embodiments.

Embodiment one,

As shown in FIG. 2 , it is a flow chart of a DC component control method for a three-phase inverter in Embodiment 1 of the present invention, including the following steps:

Step S201, detecting the output voltage of the three-phase inverter and the DC component of the output voltage. Let the detected output voltages of the three-phase inverter be Ua, Ub, and Uc, and the output voltages are Ua, Ub, and Uc to obtain the DC components Uade, Ubde, and Ucdc of the three-phase inverter output voltage through the DC component detection circuit. In one embodiment of the present invention, the DC component of the output voltage of the three-phase inverter is detected by a second-order low-pass filter with a cutoff frequency of about 1 Hz. As shown in FIG. 3 , it is a schematic diagram of a second-order low-pass filter in an embodiment of the present invention.

Step S202, converting the DC components Uadc, Ubdc, and Ucdc of the output voltage from a/b/c static coordinates to d/q/0 rotating coordinates to obtain components Udde, Uqdc, and U0de of the DC components above the rotating coordinates . Specifically, d/q/0 rotating coordinate system transformation is performed on the obtained filtered voltage DC components Uadc, Ubdc, and Uedc. The dq0 transformation matrix is as follows:

Step S203, calculating the DC voltage adjustment value according to the components Udde, Uqdc, U0dc of the DC component on the d/q/0 rotation coordinate and the DC voltage given value. In one embodiment of the present invention, the DC voltage given value is zero.

Step S204, calculating a given voltage value of the three-phase inverter according to the DC voltage adjustment value and the reference output voltage of the three-phase inverter. This step is calculated by a DC component controller, which may be a proportional-integral (PI) controller, or other controllers such as a PID controller.

Step S205, calculating the output adjustment voltage of the three-phase inverter according to the given voltage value and the output voltage of the three-phase inverter. This step is the same as the existing space vector control, so it will not be repeated here. As mentioned above, only the voltage loop or a combination of the voltage loop and the current loop may be included in this step.

For example, corresponding to the d-axis component, the d-axis component of the sampled DC voltage is used as the feedback value of the d-axis DC voltage regulator, which is subtracted from the given value of the d-axis DC voltage (set to 0), and the DC component The controller regulates the operation. The output of the DC component controller is added to the d-axis voltage reference value of the inverter, and is calculated by the d-axis inverter controller to obtain the d-axis component control signal (that is, the output adjustment voltage). Corresponding to the q-axis component, the q-axis component of the sampled DC voltage is used as the feedback amount of the q-axis DC voltage regulator, which is subtracted from the given value of the q-axis DC voltage (set to 0) to perform a DC component controller Regulatory operations. The output of the DC component controller is added to the q-axis voltage reference value of the inverter, and is calculated by the q-axis inverter controller to obtain the q-axis component control signal. Corresponding to the 0-axis component, the 0-axis component of the sampled DC voltage is used as the feedback amount of the 0-axis DC voltage regulator, and is subtracted from the 0-axis DC voltage given value (set to 0) to perform a DC component controller Regulatory operations. The output of the DC component controller is added to the 0-axis voltage reference value of the inverter, and is calculated by the 0-axis inverter controller to obtain the 0-axis component control signal.

Step S206 , converting the output adjustment voltage of the three-phase inverter from d/q/0 rotating coordinates to a/b/c stationary coordinates and performing PWM modulation to obtain driving signals of the three-phase inverter.

Step S207, performing driving control on the three-phase inverter according to the driving signal of the three-phase inverter so as to eliminate the DC component in the output voltage.

As shown in FIG. 4 , it is a structural diagram of a DC component control system for a three-phase inverter according to Embodiment 1 of the present invention. The system includes a three-phase inverter 100 , a detection module 200 , a controller 300 and a driving module 400 . The detection module 200 is used for detecting the output voltage of the three-phase inverter 100 and the DC component of the output voltage. The controller 300 is used to convert the DC component of the output voltage from stationary coordinates to rotating coordinates to obtain the components of the DC component above the rotating coordinates, and calculate the DC Voltage adjustment value, and calculate the voltage given value of the three-phase inverter according to the DC voltage adjustment value and the reference output voltage of the three-phase inverter, and the output voltage according to the voltage given value and the three-phase inverter 100 voltage loop Calculate the output adjustment voltage of the three-phase inverter, and convert the output adjustment voltage of the three-phase inverter 100 into a stationary coordinate and perform PWM modulation to obtain the driving signal of the three-phase inverter 100 . The driving module 400 is used for controlling the driving of the three-phase inverter 100 according to the driving signal of the three-phase inverter 100 obtained by the controller 300 so as to eliminate the DC component in the output voltage.

In one embodiment of the present invention, the above-mentioned DC voltage given value is zero.

In one embodiment of the present invention, the detection module 200 is a second-order low-pass filter with a cutoff frequency of 1 Hz.

As shown in FIG. 5 , it is a structural diagram of a controller according to Embodiment 1 of the present invention. The controller 300 includes a first conversion module 310 , a DC controller 320 , an inverter controller 330 , a second conversion module 340 and a PWM modulation module 350 . The first conversion module 310 is used for converting the DC component of the output voltage from the stationary coordinate to the rotating coordinate to obtain a component of the DC component above the rotating coordinate. The DC controller 320 is used to calculate the DC voltage adjustment value according to the component of the DC component above the rotating coordinate and the DC voltage given value, and calculate the three-phase voltage according to the DC voltage adjustment and the reference output voltage of the three-phase inverter. The voltage reference value of the inverter. The inverter controller 330 is used for calculating the output adjustment voltage of the three-phase inverter according to the given voltage value and the output voltage of the three-phase inverter. The second conversion module 340 is used for converting the output adjustment voltage of the three-phase inverter from the rotating coordinates to the stationary coordinates. The PWM modulation module 350 is used to perform PWM modulation on the converted output adjustment voltage to obtain the driving signal of the three-phase inverter.

Embodiment two,

As shown in FIG. 6, it is a flowchart of a DC component control method for a single-phase inverter according to Embodiment 2 of the present invention, including the following steps:

Step S601, constructing the structure of the three-phase inverter according to the structure of the single-phase inverter, and using the single-phase inverter as the first phase of the three-phase inverter. It should be noted that, in the embodiment of the present invention, the single-phase inverter can be used as any phase of the three-phase inverter, which can be A phase, B phase or C phase, so the above-mentioned first phase Can be A phase, B phase or C phase. In the embodiments of the present invention, the single-phase inverter is used as the A-phase as an example for description. Compared with the three-phase inverter, the single-phase inverter lacks the required complete three-phase power supply signal and topology structure, so it is necessary to construct the topology structure of B and C two phases and the corresponding transfer function virtually, so as to meet the requirements of vector control. Requirements for three-phase power supply. As an implementation example of the present invention, as shown in FIG. 7 , it is a topology circuit structure of a half-bridge three-phase inverter constructed in Embodiment 2 of the present invention. Wherein, in this embodiment, the B-phase and C-phase circuits are virtual circuits whose structure is the same as that of the A-phase circuit. Among them, E1 and E2 are the positive and negative DC BUS voltages, Q1 and Q2 are the driving transistors (IGBTs) of the actual single-phase inverter, the inductor L1 and the capacitor C1 are the actual filter circuit, and RI is the load. Among them, Q3-Q6 are virtual two-phase drive transistors, L2 and L3 are virtual inductors, C2 and C3 are virtual capacitors, and R2 and R3 are virtual loads. Wherein, the same inductance value is set as L, the same capacitance value is set as C, and the same load is set as R.

Step S602, detecting the output voltage of the single-phase inverter and the DC component of the output voltage, and using it as the first output voltage of the first phase of the constructed three-phase inverter and the first direct current component of the first output voltage amount of traffic. In one embodiment of the present invention, the DC component of the output voltage of the three-phase inverter is detected by a second-order low-pass filter with a cutoff frequency of about 1 Hz.

Step S603, calculating the second output voltage of the second phase and the third output voltage of the third phase in the three-phase inverter according to the structure of the constructed three-phase inverter and the first output voltage of the first phase , and set the second DC component of the second output voltage and the third DC component of the third output voltage to zero.

Step S604, transforming the first DC component, the second DC component, and the third DC component from stationary coordinates to rotating coordinates to obtain the coordinates of the first DC component, the second DC component, and the third DC component above the rotating coordinates portion.

Step S605, according to the components of the first DC component, the second DC component and the third DC component above the rotating coordinates, the first DC voltage given value of the first phase, and the second DC voltage given value of the second phase Calculate the first DC voltage adjustment value of the first phase, the second DC voltage adjustment value of the second phase and the third DC voltage adjustment value of the third phase with the third DC voltage given value of the third phase. In one embodiment of the present invention, the first given DC voltage value, the second given DC voltage value and the third given DC voltage value are all zero.

Step S606, according to the first DC voltage adjustment value, the second DC voltage adjustment value and the third DC voltage adjustment value, and the first reference output voltage, the second reference output voltage and the third reference output voltage of the three-phase inverter respectively A first voltage setpoint for the first phase, a second voltage setpoint for the second phase, and a third voltage setpoint for the third phase are calculated. In one embodiment of the present invention, the first reference output voltage is a given voltage amplitude Vmax of the single-phase inverter voltage loop, and the second reference output voltage and the third reference output voltage are zero.

Step S607, calculating the first output adjustment voltage of the first phase according to the first given voltage value, the second given voltage value and the third given voltage value, as well as the first output voltage, the second output voltage and the third output voltage , the second output regulation voltage of the second phase and the third output regulation voltage of the third phase.

Step S608, transforming the first output adjustment voltage, the second output adjustment voltage and the third output adjustment voltage from the rotating coordinates to the stationary coordinates and performing PWM modulation to obtain the first driving signal of the first phase, the The second driving signal of the second phase and the third driving signal of the third phase.

Step S609, performing driving control on the single-phase inverter according to the first driving signal.

In a preferred embodiment of the present invention, since phase B and phase C are virtual, it is also necessary to calculate the output voltage of the second phase and the output voltage of the third phase according to the second driving signal and the third driving signal, And according to the output voltage of the second phase and the output voltage of the third phase, the output voltages of the second phase and the third phase are calculated, so as to ensure the stable operation of the simulated three-phase inverter.

As shown in FIG. 8 , it is a structural diagram of a DC component control system for a single-phase inverter according to Embodiment 2 of the present invention. The system includes a single-phase inverter 500 , a detection module 600 , a controller 700 and a drive module 800 . The detection module 600 is used to detect the output voltage of the single-phase inverter 500 and the DC component of the output voltage. The controller 700 is configured to save the structure of the three-phase inverter configured according to the structure of the single-phase inverter, wherein the single-phase inverter is the first phase of the three-phase inverter. The controller 700 is further configured to use the output voltage of the single-phase inverter 500 detected by the detection module 600 and the DC component of the output voltage as the first output voltage of the first phase and the first DC component of the first output voltage, and calculating the second output voltage of the second phase in the three-phase inverter according to the structure of the three-phase inverter of the construction and the first output voltage of the first phase, and the third output of the third phase voltage, and setting the second DC component of the second output voltage and the third DC component of the third output voltage to zero. The controller 700 is also used to convert the first DC component, the second DC component and the third DC component from stationary coordinates to rotating coordinates to obtain the first DC component, the second DC component and the third DC component in the described a component on the rotating coordinate, and a component on the rotating coordinate according to the first direct current component, the second direct current component and the third direct current component and the first direct current voltage given value of the first phase, The second DC voltage given value of the second phase and the third DC voltage given value of the third phase calculate the first DC voltage adjustment value of the first phase, and the second DC voltage of the second phase voltage adjustment value and the third direct current voltage adjustment value of the third phase. The controller 700 is further configured to adjust the value according to the first DC voltage, the second DC voltage and the third DC voltage, and the first reference output voltage, the second reference output voltage and the first reference output voltage of the three-phase inverter. The three reference output voltages respectively calculate the first voltage given value of the first phase, the second voltage given value of the second phase and the third voltage given value of the third phase. The controller 700 is also used to calculate the first phase voltage of the first phase according to the first given voltage value, the second given voltage value and the third given voltage value, as well as the first output voltage, the second output voltage and the third output voltage. An output regulated voltage, a second output regulated voltage of the second phase, and a third output regulated voltage of the third phase. The controller 700 is further configured to convert the first output adjustment voltage, the second output adjustment voltage, and the third output adjustment voltage from the rotating coordinates to the stationary coordinates and perform PWM modulation to obtain the first phase of the first phase. a driving signal, a second driving signal of the second phase, and a third driving signal of the third phase. The driving module 800 is used for driving and controlling the single-phase inverter 500 according to the first driving signal. In one embodiment of the present invention, the first given DC voltage value, the second given DC voltage value and the third given DC voltage value are all zero.

In an embodiment of the present invention, the controller 700 is further configured to calculate the output voltage of the second phase and the output voltage of the third phase according to the second driving signal and the third driving signal.

In one embodiment of the present invention, the detection module 600 is a second-order low-pass filter with a cutoff frequency of 1 Hz.

As shown in FIG. 9 , it is a structural diagram of the controller of Embodiment 2 of the present invention. The controller 700 includes an output calculation module 710 , a first conversion module 720 , a DC controller 730 , an inverter controller 740 , a second conversion module 750 and a PWM modulation module 760 . The output calculation module 710 is used to use the output voltage of the single-phase inverter detected by the detection module 600 and the DC component of the output voltage as the first output voltage of the first phase and the first DC component of the first output voltage, and according to the calculating the second output voltage of the second phase and the third output voltage of the third phase in the three-phase inverter based on the structure of the three-phase inverter of the above structure and the first output voltage of the first phase, and The second DC component of the second output voltage and the third DC component of the third output voltage are set to zero. The first conversion module 720 is configured to convert the first DC component, the second DC component and the third DC component from stationary coordinates to rotating coordinates to obtain the first DC component, the second DC component and the third DC component The component above the rotated coordinate. The direct current controller 730 is used for according to the components of the first direct current component, the second direct current component and the third direct current component above the rotation coordinates and the first direct current voltage given value of the first phase, the second direct current component The second DC voltage given value of the phase and the third DC voltage given value of the third phase calculate the first DC voltage adjustment value of the first phase, the second DC voltage adjustment value of the second phase and The third DC voltage adjustment value of the third phase, and according to the first DC voltage adjustment value, the second DC voltage adjustment value and the third DC voltage adjustment value, and the first reference of the three-phase inverter The output voltage, the second reference output voltage and the third reference output voltage respectively calculate the first voltage given value of the first phase, the second voltage given value of the second phase and the third voltage given value of the third phase Value. The inverter controller 740 is used to calculate the first voltage value according to the first voltage value, the second voltage value and the third voltage value, and the first output voltage, the second output voltage and the third output voltage. A first output regulated voltage of one phase, a second output regulated voltage of the second phase and a third output regulated voltage of the third phase. The second conversion module 750 is used for converting the first output adjustment voltage, the second output adjustment voltage and the third output adjustment voltage from the rotating coordinates to the stationary coordinates. The PWM modulation module 760 is configured to perform PWM modulation on the converted first output adjustment voltage, second output adjustment voltage, and third output adjustment voltage to obtain the first driving signal of the first phase, the first driving signal of the second phase, and the first driving signal of the second phase. the second drive signal and the third drive signal of the third phase.

The present invention controls the direct current component in the output voltage of the inverter through space vector control, thereby effectively reducing the direct current component in the output voltage of the inverter to meet the load requirement. Moreover, the DC component vector control of the present invention can be used in combination with the current space vector control mode, so it is simple and reliable without increasing the cost.

Although the embodiments of the present invention have been shown and described, those skilled in the art can understand that various changes, modifications and substitutions can be made to these embodiments without departing from the principle and spirit of the present invention. and modifications, the scope of the invention is defined by the appended claims and their equivalents.

Claims (16)

1. a DC component control method that is used for three-phase inverter is characterized in that, may further comprise the steps:

Detect the DC component of the output voltage and the said output voltage of said three-phase inverter;

The conversion of the DC component of said output voltage being carried out static coordinate to rotational coordinates is to obtain the component of said DC component on said rotational coordinates;

Calculate the direct voltage adjusted value according to the component and the direct voltage set-point of said DC component on said rotational coordinates;

Calculate the voltage given value of said three-phase inverter according to the reference output voltage of said direct voltage adjusted value and said three-phase inverter;

Calculate the output adjustment voltage of said three-phase inverter according to the output voltage of said voltage given value and said three-phase inverter;

The output of said three-phase inverter adjustment voltage is carried out the conversion of said rotational coordinates to said static coordinate and go forward side by side horizontal pulse width modulated PWM modulation to obtain the drive signal of said three-phase inverter; With

Drive signal according to said three-phase inverter is carried out drive controlling to said three-phase inverter.

2. the DC component control method that is used for three-phase inverter as claimed in claim 1 is characterized in that, said direct voltage set-point is zero.

3. the DC component control method that is used for three-phase inverter as claimed in claim 1 is characterized in that, detects the DC component of said three-phase inverter output voltage through low pass filter.

4. a DC component control system that is used for three-phase inverter is characterized in that, comprising:

Three-phase inverter;

Detection module is used to detect the DC component of the output voltage and the said output voltage of said three-phase inverter;

Controller; The conversion that is used for the DC component of said output voltage is carried out static coordinate to rotational coordinates is to obtain the component of said DC component on said rotational coordinates; And according to component and the direct voltage set-point calculating direct voltage adjusted value of said DC component on said rotational coordinates; And the voltage given value of calculating said three-phase inverter according to the reference output voltage of said direct voltage adjusted value and said three-phase inverter; Calculate the output adjustment voltage of said three-phase inverter with output voltage, and the conversion that the output adjustment voltage of said three-phase inverter carries out said rotational coordinates to said static coordinate is gone forward side by side horizontal pulse width modulated PWM modulation to obtain the drive signal of said three-phase inverter according to said voltage given value and said three-phase inverter; With

Driver module, the drive signal of the three-phase inverter that is used for obtaining according to said controller is carried out drive controlling to said three-phase inverter.

5. the DC component control system that is used for three-phase inverter as claimed in claim 4 is characterized in that, said direct voltage set-point is zero.

6. the DC component control system that is used for three-phase inverter as claimed in claim 4 is characterized in that said detection module is a low pass filter.

7. the DC component control system that is used for three-phase inverter as claimed in claim 4 is characterized in that said controller comprises:

First modular converter, the conversion that is used for the DC component of said output voltage is carried out static coordinate to rotational coordinates is to obtain the component of said DC component on said rotational coordinates;

Dc controller; Be used for calculating the direct voltage adjusted value, and calculate the voltage given value of said three-phase inverter according to the reference output voltage of said direct voltage adjustment and said three-phase inverter according to the component and the direct voltage set-point of said DC component on said rotational coordinates;

Inverter controller is used for the output adjustment voltage that output voltage according to said voltage given value and said three-phase inverter calculates said three-phase inverter;

Second modular converter is used for the output adjustment voltage of said three-phase inverter is carried out the conversion of said rotational coordinates to said static coordinate;

The pulse width modulation (PWM) modulation module is used for the adjustment of the output after conversion voltage is carried out the PWM modulation to obtain the drive signal of said three-phase inverter.

8. a DC component control method that is used for single-phase inverter is characterized in that, may further comprise the steps:

According to the structure of the structure construction three-phase inverter of said single-phase inverter, and with said single-phase inverter as first phase in the said three-phase inverter;

Detect the DC component of the output voltage and the said output voltage of said single-phase inverter, and with its first DC component as first output voltage and said first output voltage of said first phase;

Calculate second output voltage of second phase in the said three-phase inverter according to first output voltage of the structure of the three-phase inverter of said structure and said first phase; And the 3rd output voltage of third phase, and be made as second DC component of said second output voltage and the 3rd DC component of the 3rd output voltage zero;

The conversion of said first DC component, second DC component and the 3rd DC component being carried out static coordinate to rotational coordinates is to obtain said first DC component, second DC component and the component of the 3rd DC component on said rotational coordinates;

Calculate said first mutually the first direct voltage adjusted value, second direct voltage adjusted value of said second phase and the 3rd direct voltage adjusted value of said third phase according to the 3rd direct voltage set-point of the second direct voltage set-point of mutually the first direct voltage set-point of said first DC component, second DC component and the 3rd DC component component and said first on said rotational coordinates, said second phase and said third phase;

According to the said first direct voltage adjusted value, the second direct voltage adjusted value and the 3rd direct voltage adjusted value, and first reference output voltage of said three-phase inverter, second reference output voltage and the 3rd reference output voltage calculate said first mutually the first voltage given value, the second voltage given value of said second phase and the tertiary voltage set-point of said third phase respectively;

According to the said first voltage given value, the second voltage given value and tertiary voltage set-point, and said first output voltage, second output voltage and the 3rd output voltage calculate said first mutually the first output adjustment voltage, the second output adjustment voltage of said second phase and the 3rd output adjustment voltage of said third phase;

The said first output adjustment voltage, the second output adjustment voltage and the 3rd output adjustment voltage are carried out the conversion of said rotational coordinates to said static coordinate and carries out the PWM modulation to obtain said first mutually first drive signal, second drive signal of said second phase and the 3rd drive signal of said third phase; With

According to said first drive signal said single-phase inverter is carried out drive controlling.

9. the DC component control method that is used for single-phase inverter as claimed in claim 8 is characterized in that, the said first direct voltage set-point, the said second direct voltage set-point and said the 3rd direct voltage set-point are zero.

10. the DC component control method that is used for single-phase inverter as claimed in claim 8 is characterized in that, also comprises:

Calculate said second mutually output voltage and the output voltage of said third phase according to said second drive signal and the 3rd drive signal.

11. the DC component control method that is used for single-phase inverter as claimed in claim 8 is characterized in that, detects the DC component of said three-phase inverter output voltage through low pass filter.

12. a DC component control system that is used for single-phase inverter is characterized in that, comprising:

Single-phase inverter;

Detection module is used to detect the DC component of the output voltage and the said output voltage of said single-phase inverter;

Controller is configured in order to carry out following function:

Be used to preserve the structure according to the three-phase inverter of the structure construction of said single-phase inverter, wherein, said single-phase inverter is first phase in the said three-phase inverter;

The output voltage of the said single-phase inverter that is used for said detection module is detected and the DC component of output voltage are as said first mutually first output voltage and first DC component of said first output voltage; And second output voltage that calculates second phase in the said three-phase inverter according to first output voltage of the structure of the three-phase inverter of said structure and said first phase; And the 3rd output voltage of third phase, and be made as second DC component of said second output voltage and the 3rd DC component of the 3rd output voltage zero;

The conversion that is used for said first DC component, second DC component and the 3rd DC component are carried out static coordinate to rotational coordinates is to obtain said first DC component, second DC component and the component of the 3rd DC component on said rotational coordinates; And calculate said first mutually the first direct voltage adjusted value, second direct voltage adjusted value of said second phase and the 3rd direct voltage adjusted value of said third phase according to the 3rd direct voltage set-point of the second direct voltage set-point of mutually the first direct voltage set-point of said first DC component, second DC component and the 3rd DC component component and said first on said rotational coordinates, said second phase and said third phase;

Be used for according to the said first direct voltage adjusted value, the second direct voltage adjusted value and the 3rd direct voltage adjusted value, and first reference output voltage of said three-phase inverter, second reference output voltage and the 3rd reference output voltage calculate said first mutually the first voltage given value, the second voltage given value of said second phase and the tertiary voltage set-point of said third phase respectively;

Be used for according to the said first voltage given value, the second voltage given value and tertiary voltage set-point, and said first output voltage, second output voltage and the 3rd output voltage calculate said first mutually the first output adjustment voltage, the second output adjustment voltage of said second phase and the 3rd output adjustment voltage of said third phase;

Be used for the said first output adjustment voltage, the second output adjustment voltage and the 3rd output adjustment voltage are carried out the conversion of said rotational coordinates to said static coordinate and carries out the PWM modulation to obtain said first mutually first drive signal, second drive signal of said second phase and the 3rd drive signal of said third phase; With

Driver module is used for according to said first drive signal said single-phase inverter being carried out drive controlling.

13. the DC component control system that is used for single-phase inverter as claimed in claim 12 is characterized in that, the said first direct voltage set-point, the said second direct voltage set-point and said the 3rd direct voltage set-point are zero.

14. the DC component control system that is used for single-phase inverter as claimed in claim 12; It is characterized in that said controller also is used for calculating said second mutually output voltage and the output voltage of said third phase according to said second drive signal and the 3rd drive signal.

15. the DC component control system that is used for single-phase inverter as claimed in claim 12 is characterized in that said detection module is a low pass filter.

16. the DC component control system that is used for single-phase inverter as claimed in claim 12 is characterized in that said controller comprises:

The output computing module; The output voltage of the said single-phase inverter that is used for said detection module is detected and the DC component of output voltage are as said first mutually first output voltage and first DC component of said first output voltage; And second output voltage that calculates second phase in the said three-phase inverter according to first output voltage of the structure of the three-phase inverter of said structure and said first phase; And the 3rd output voltage of third phase, and be made as second DC component of said second output voltage and the 3rd DC component of the 3rd output voltage zero;

First modular converter, the conversion that is used for said first DC component, second DC component and the 3rd DC component are carried out static coordinate to rotational coordinates is to obtain said first DC component, second DC component and the component of the 3rd DC component on said rotational coordinates;

Dc controller; Be used for the 3rd direct voltage set-point according to the second direct voltage set-point of mutually the first direct voltage set-point of said first DC component, second DC component and the 3rd DC component component and said first on said rotational coordinates, said second phase and said third phase and calculate said first mutually the first direct voltage adjusted value; Second direct voltage adjusted value of said second phase and the 3rd direct voltage adjusted value of said third phase; And according to the said first direct voltage adjusted value, the second direct voltage adjusted value and the 3rd direct voltage adjusted value, and first reference output voltage of said three-phase inverter, second reference output voltage and the 3rd reference output voltage calculate said first mutually the first voltage given value, the second voltage given value of said second phase and the tertiary voltage set-point of said third phase respectively;

Inverter controller; Be used for according to the said first voltage given value, the second voltage given value and tertiary voltage set-point, and said first output voltage, second output voltage and the 3rd output voltage calculate said first mutually the first output adjustment voltage, the second output adjustment voltage of said second phase and the 3rd output adjustment voltage of said third phase;

Second modular converter is used for the said first output adjustment voltage, the second output adjustment voltage and the 3rd output adjustment voltage are carried out the conversion of said rotational coordinates to said static coordinate; With

The PWM modulation module is used for the first output adjustment voltage after the conversion, the second output adjustment voltage and the 3rd output adjustment voltage are carried out the PWM modulation to obtain said first mutually first drive signal, second drive signal of said second phase and the 3rd drive signal of said third phase.

Images