阅读说明：本技术 一种可同时补偿电网谐波与无功电流的并联型Boost PFC系统 (Parallel Boost PFC system capable of simultaneously compensating harmonic waves and reactive current of power grid ) 是由 代云中 张荣飞 施渊吉 罗钟雨 李宁 陈琪 屈珣 胡伟龙 张鑫坤 刘健洋 冷云松 于 2021-08-30 设计创作，主要内容包括：本发明公开了一种可同时补偿电网谐波与无功电流的并联型BoostPFC系统,属于谐波与无功补偿技术领域,该可同时补偿电网谐波与无功电流的并联型BoostPFC系统包括线路电阻Rg、电感Lg、变换器电源驱动负载RLd、BoostPFC变换器、补偿控制器、非线性负载、网侧电压us,所述网侧电压us一端与所述电感Lg连接,电感Lg另一端与所述线路电阻Rg连接,线路电阻Rg另一端并联所述BoostPFC变换器、补偿控制器、非线性负载；该并联型BoostPFC系统不仅能对低压配电网网侧谐波与无功进行同时补偿,还能保证自身非线性负载的稳定工作。(The invention discloses a parallel type boost PFC system capable of simultaneously compensating power grid harmonic waves and reactive currents, which belongs to the technical field of harmonic wave and reactive compensation and comprises a line resistor Rg, an inductor Lg, a converter power supply driving load RLd, a boost PFC converter, a compensation controller, a nonlinear load and a line side voltage us, wherein one end of the line side voltage us is connected with the inductor Lg, the other end of the inductor Lg is connected with the line resistor Rg, and the other end of the line resistor Rg is connected with the boost PFC converter, the compensation controller and the nonlinear load in parallel; the parallel type BoostPFC system can not only simultaneously compensate the network side harmonic waves and the reactive power of the low-voltage power distribution network, but also ensure the stable work of self nonlinear loads.)

1. The parallel Boost PFC system capable of simultaneously compensating the harmonic waves and the reactive currents of the power grid is characterized by comprising a line resistor Rg, an inductor Lg, a converter power supply driving load RLd, a Boost PFC converter, a compensation controller, a nonlinear load and a line side voltage us, wherein one end of the line side voltage us is connected with the inductor Lg, the other end of the inductor Lg is connected with the line resistor Rg, and the other end of the line resistor Rg is connected with the Boost PFC converter, the compensation controller and the nonlinear load in parallel.

2. The parallel Boost PFC system capable of simultaneously compensating power grid harmonic and reactive current according to claim 1 is characterized in that the Boost PFC converter comprises a compensation signal tracking control circuit, a driving circuit, a main circuit and a filter circuit, wherein one end of the compensation signal tracking control circuit is connected with the compensation controller, the connection end of the compensation signal tracking control circuit and the compensation controller is controlled through a compensation signal vc, the other end of the compensation signal tracking control circuit is connected to the driving circuit, the other end of the driving circuit is connected with the main circuit, the other end of the main circuit is connected with the filter circuit, the other end of the filter circuit is connected to a line resistor Rg, and a converter power supply driving load RLd is further connected to the main circuit.

3. The parallel Boost PFC system capable of simultaneously compensating for power grid harmonics and reactive current according to claim 2, wherein the compensation controller comprises a control compensation circuit, one end of the control compensation circuit is connected with a line resistor Rg, and the other end of the control compensation circuit is connected to the compensation signal tracking control circuit.

4. The parallel Boost PFC system capable of simultaneously compensating the harmonic wave and the reactive current of the power grid according to claim 3, wherein the control compensation circuit comprises a current input, a detection current is obtained through digital-to-analog conversion after the circuit input, an ideal compensation signal is obtained through harmonic wave and reactive current detection and active current detection, the ideal compensation signal is evaluated through an absolute value, and a compensation signal vc is obtained through digital-to-analog conversion again.

5. The parallel Boost PFC system capable of simultaneously compensating harmonic waves and reactive currents of a power grid according to claim 2, wherein the compensation signal vc is converted into a Boost PFC converter current iC through a Boost PFC converter, a specific conversion circuit comprises a voltage outer loop circuit formed by an amplifier EA1, a voltage inner loop circuit formed by an amplifier EA2 and a voltage comparator EC1, and the voltage comparator EC1 receives a current signal generated by a grid-side voltage us.

Technical Field

The invention belongs to the technical field of harmonic and reactive compensation, and particularly relates to a parallel Boost PFC system capable of simultaneously compensating harmonic and reactive current of a power grid.

Background

In recent years, the large use of nonlinear loads brings different degrees of power quality problems to low-voltage distribution networks, wherein the harmonic and reactive problems are the most serious. Active Power Factor Correction (APFC) converters widely applied to a driving Power supply side are used for Active management, while passive management is centralized management from a network side by adding additional devices, such as Active Power Filters (APF), wherein Active management is a more ideal management mode, but based on the consideration of economic cost, a large number of small-Power nonlinear devices do not have a Power Factor Correction function, and further the management difficulty of harmonic and reactive of a distribution network is increased.

The traditional PFC technology is only used for realizing power factor correction and harmonic suppression emission of a single power supply, and along with the development of the power electronic technology, on the premise of not changing the structure of a power distribution network and not increasing an additional compensation device, the control scheme for realizing low-voltage distribution network harmonic and reactive current compensation by changing the control strategy of the traditional PFC converter can provide an effective solution for low-voltage distribution network harmonic and reactive power control.

In the prior art, 1, in 2016, a clustered flyback LED driver with power factor correction is proposed to be used for eliminating harmonic current in an intelligent power distribution system by using an LED lighting driver in an IEEE 17 th power electronic control and modeling workshop (comp el), and the waveform of human current output by a converter is controlled by calculating the conduction time of a switching tube, so that the purpose of harmonic and reactive compensation of a distribution network is achieved, but the problem of single harmonic compensation with phases of 0 and pi is explained for the flyback LED driver with a PFC only through a Simulink simulation experiment, and a specific compensation scheme for compensating harmonic and reactive current at the side of a low-voltage distribution network is not actually proposed; 2. the harmonic compensation method of the power distribution system of Y.W.Li and J.He and the harmonic compensation of the residential power distribution system adopting a photovoltaic interface inverter of S.Munir and Y.W.Li.Resiential propose that the harmonic compensation of a low-voltage distribution network is realized by using a renewable energy (light and wind) power converter under the condition of not full load work, however, the solution depends on whether the installation point has the exploitation value of renewable energy, and is greatly influenced by environmental factors.

Disclosure of Invention

The invention aims to provide a parallel Boost PFC system capable of simultaneously compensating harmonic waves and reactive currents of a power grid.

In order to achieve the purpose, the invention provides the following technical scheme: the parallel Boost PFC system capable of simultaneously compensating the harmonic waves and the reactive currents of the power grid comprises a line resistor Rg, an inductor Lg, a converter power supply driving load RLd, a Boost PFC converter, a compensation controller, a nonlinear load and a line side voltage us, wherein one end of the line side voltage us is connected with the inductor Lg, the other end of the inductor Lg is connected with the line resistor Rg, and the other end of the line resistor Rg is connected with the Boost PFC converter, the compensation controller and the nonlinear load in parallel.

Preferably, the Boost PFC converter comprises a compensation signal tracking control circuit, a driving circuit, a main circuit and a filter circuit, wherein one end of the compensation signal tracking control circuit is connected with the compensation controller, the connection end of the compensation signal tracking control circuit and the compensation controller is controlled through a compensation signal vc, the other end of the compensation signal tracking control circuit is connected to the driving circuit, the other end of the driving circuit is connected with the main circuit, the other end of the main circuit is connected with the filter circuit, the other end of the filter circuit is connected to the line resistor Rg, and the main circuit is further connected with a converter power supply driving load RLd.

Preferably, the compensation controller comprises a control compensation circuit, one end of the control compensation circuit is connected with the line resistor Rg, and the other end of the control compensation circuit is connected to the compensation signal tracking control circuit.

Preferably, the control compensation circuit comprises a current input, the circuit input is subjected to digital-to-analog conversion to obtain a detection current, the detection current is subjected to harmonic and reactive current detection and active current detection to obtain an ideal compensation signal, the ideal compensation signal is subjected to absolute value evaluation, and the digital-to-analog conversion is performed again to obtain a compensation signal vc.

Preferably, the compensation signal vc is converted into a Boost PFC converter current iC through a Boost PFC converter, and the specific conversion circuit includes a voltage outer loop circuit formed by an amplifier EA1, a voltage inner loop circuit formed by an amplifier EA2, and a voltage comparator EC1, and the voltage comparator EC1 receives a current signal generated from the grid-side voltage us.

The invention has the beneficial effects that: according to the invention, a single-phase parallel structure is established, and when harmonic and reactive are compensated simultaneously on the premise of not changing the structure of a power distribution network and not adding an additional compensation device, the Boost PFC converter controlled by average current can effectively compensate network side current harmonic and reactive and ensure the stable work of self-driven load, and the converter can realize the compensation of network side harmonic and reactive current while maintaining the stable work of self-driven load.

Drawings

Fig. 1 is a structural diagram of a Boost PFC converter system of a parallel Boost PFC system capable of simultaneously compensating a harmonic wave and a reactive current of a power grid according to the present invention;

fig. 2 is a control block diagram of a compensation controller of a parallel Boost PFC system capable of simultaneously compensating a harmonic wave and a reactive current of a power grid according to the present invention;

fig. 3 is a circuit structure diagram of a Boost PFC converter of a parallel Boost PFC system capable of simultaneously compensating a harmonic wave and a reactive current of a power grid according to the present invention;

fig. 4 iS a waveform diagram of US, iC, iS before harmonic and reactive compensation in a test of a parallel Boost PFC system capable of simultaneously compensating a power grid harmonic and reactive current provided by the present invention;

fig. 5 is a schematic diagram of harmonic and reactive compensation in a test of a parallel Boost PFC system capable of simultaneously compensating a power grid harmonic and reactive current provided by the invention.

Detailed Description

In order to further understand the contents, features and effects of the present invention, the following embodiments are illustrated and described in detail with reference to the accompanying drawings.

Referring to fig. 1 to 5, a parallel Boost PFC system capable of simultaneously compensating a harmonic and a reactive current of a power grid according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

The parallel Boost PFC system capable of simultaneously compensating power grid harmonic waves and reactive currents comprises a line resistor Rg, an inductor Lg, a converter power supply driving load RLd, a Boost PFC converter, a compensation controller, a nonlinear load and a line side voltage us, wherein one end of the line side voltage us is connected with the inductor Lg, the other end of the inductor Lg is connected with the line resistor Rg, and the other end of the line resistor Rg is connected with the Boost PFC converter, the compensation controller and the nonlinear load in parallel.

Specifically, the Boost PFC converter comprises a compensation signal tracking control circuit, a driving circuit, a main circuit and a filter circuit, wherein one end of the compensation signal tracking control circuit is connected with the compensation controller, the connecting end of the compensation signal tracking control circuit and the compensation controller is controlled through a compensation signal vc, the other end of the compensation signal tracking control circuit is connected to the driving circuit, the other end of the driving circuit is connected with the main circuit, the other end of the main circuit is connected with the filter circuit, the other end of the filter circuit is connected to a line resistor Rg, and the main circuit is further connected with a converter power supply driving load RLd.

Specifically, the compensation controller comprises a control compensation circuit, one end of the control compensation circuit is connected with the line resistor Rg, and the other end of the control compensation circuit is connected to the compensation signal tracking control circuit.

Specifically, the control compensation circuit comprises a current input, a detection current is obtained through digital-to-analog conversion after the circuit input, an ideal compensation signal is obtained through harmonic and reactive current detection and active current detection of the detection current, the ideal compensation signal is evaluated through an absolute value, and a compensation signal vc is obtained through digital-to-analog conversion again.

Specifically, the compensation signal vc is converted into a Boost PFC converter current iC through a Boost PFC converter, and the specific conversion circuit includes a voltage outer loop circuit formed by an amplifier EA1, a voltage inner loop circuit formed by an amplifier EA2, and a voltage comparator EC1, wherein the voltage comparator EC1 receives a current signal generated by the grid-side voltage us.

For the voltage outer loop circuit and the voltage inner loop circuit, the voltage outer loop stabilizes output voltage and ensures the stable work of self load, and the output vv-EA of the voltage outer loop circuit can be expressed as

Wherein Vref is a reference voltage, V0 is a converter output voltage, and k1 is an output voltage sampling coefficient;

the current inner loop enables tracking of a current given signal iref, whose output vi-EA can be expressed as

v_{i_EA}＝i_refR_i-i_LR_s+v_z (2)

Wherein

Where vz is the voltage across capacitor Cz and Vff is the effective value of the input voltage. The output vi-EA of the current error amplifier is compared with the sawtooth wave to generate a PWM control signal, so that the switch Q is driven to be switched on, the tracking control of the current on the compensation signal is realized, and the absolute value of the compensation current iC is

|i_C|＝i_{L_avg}＝i_refR_m0/R_s＝kv_c (4)

Wherein

Where iL _ avg is the average value of the inductor current. From equation (5), the k value is determined by the voltage loop output, and when the converter current tracks the compensation signal well, the k value can be regarded as 1. From the formula (15) further a compensation current iC of

Furthermore, as can be seen from equation (6), the Boost PFC converter realizes the conversion of the compensation signal into the compensation current.

The parallel Boost PFC system capable of simultaneously compensating the harmonic wave and the reactive current of the power grid based on the current-multiplying capacitor network carries out simulation analysis on the nonlinear load through the PSIM. Before the harmonic and reactive compensation, the grid-side voltage, the grid-side current and the converter current are as shown in fig. 4, and at this time, the grid-side current THD is 29%, and the Power Factor (PF) of the fundamental current is 0.85. During harmonic and reactive compensation, in a power frequency period, network side voltage, an ideal compensation current signal and converter current are shown in fig. 5(a), the ideal compensation current signal is always larger than 0 in an ac section, and the cd section is always smaller than 0, at the moment, the converter can well track the compensation signal, the ideal compensation current is equal to actual compensation current, a network side current compensation result is shown in fig. 5(b), current THD is reduced to 2%, and power factor of fundamental current is improved to 0.99, so that harmonic and reactive of the network side current are well compensated.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.