CN203151392U

CN203151392U - High-efficiency low-leakage-current inverter topology

Info

Publication number: CN203151392U
Application number: CN 201320020525
Authority: CN
Inventors: 刘廷波; 张虎祥
Original assignee: TIANJIN KELIN ELECTRIC CO Ltd
Current assignee: TIANJIN KELIN ELECTRIC CO Ltd
Priority date: 2013-01-15
Filing date: 2013-01-15
Publication date: 2013-08-21
Anticipated expiration: 2023-01-15

Abstract

The utility model provides a high-efficiency low-leakage-current inverter topology comprising a loop with freewheeling and control functions, wherein the loop is composed of a bus capacitor C, first to sixth controlled switches (T1, T2, T3, T4, T5 and T6), a first filter inductor L1, a second filter inductor L2 and a filter. The high-efficiency low-leakage-current inverter topology has the following beneficial effects: high efficiency of a single-phase transformerless inverter is maintained; common-mode leakage current is reduced; and safety and reliability are improved.

Description

A kind of efficient low-leakage current inverter topology

Technical field

The utility model relates to a kind of inverter topology circuit, especially relates to a kind of efficient low-leakage current inverter topology.

Background technology

Along with the raising of the growing and human environmental consciousness of energy-consuming, widelyd popularize as the solar energy of green energy resource in recent years.Photovoltaic industry develops rapidly, the not only U.S., Japan in the world, developed countries such as Germany greatly develop solar energy generation technology, even the oil-producing country resemble Saudi Arabia also provides for a rainy day, greatly developing solar energy generation technology is photovoltaic technology, and solar energy becomes the focus that people pay close attention to.

Photovoltaic DC-to-AC converter is an important component part of photovoltaic technology.Photovoltaic DC-to-AC converter is divided into off-grid type inverter and parallel net type inverter by whether being connected to the grid.

No isolating transformer type inverter is efficiently and lightly to become main flow gradually.In single-phase transless inverter, when adopting the H bridge topology of standard, modulation system is divided into unipolarity modulation system and bipolarity modulation.

The single-phase inverter loss ratio of bipolarity modulation is bigger, most effective can only arriving about 95%, but the common mode leakage current is very little; The single-phase inverter power device switch number of times of unipolarity modulation is few, has higher efficient, and it is exactly the common mode leakage problem that unipolarity modulation simultaneously has a problem.

Summary of the invention

Problem to be solved in the utility model provides a kind of efficient low-leakage current inverter topology, especially be fit to single-phase transless inverter topology circuit, be applied directly to grid-connected, similarly be incorporated into the power networks or in the net inverter circuit from net inverter, wind power generation inverter and other.

For solving the problems of the technologies described above, the technical solution adopted in the utility model is: a kind of efficient low-leakage current inverter topology, it is characterized in that: comprise the loop with afterflow and control action, described loop comprises bus capacitor C, first to the 6th controlled switch (T1, T2, T3, T4, T5, T6), first, second filter inductance L1, L2 and filter;

Described bus capacitor C is in parallel with a direct current power supply (PV), described the first, the 3rd, the 5th controlled switch (T1, T3, T5) is connected successively, be connected in parallel on the two ends of described bus capacitor C simultaneously, described second controlled switch (T2) is in parallel with described first controlled switch (T1), described the 4th, the 6th controlled switch (T4, T6) is connected in series, and is connected in parallel on the two ends of the 3rd, the 5th controlled switch (T3, T5) simultaneously; Described the 3rd controlled switch (T3) connects a pin of the 5th controlled switch (T5), also link to each other with the described first filter inductance L1, the described first filter inductance L1 connects a pin of described filter, and another pin of described filter connects the pin that the 4th controlled switch (T4) links to each other with the 6th controlled switch (T6) by the second filter inductance L2.

Described controlled switch can be one or more the combination in IGBT, MOSFET, the silicon controlled rectifier.

Described filter is the EMC filter.

Advantage and the good effect that the utlity model has are: owing to adopt technique scheme, by increase afterflow and control loop on H bridge inverter basis, the high efficiency while keeping single-phase transless inverter reduces the common mode leakage current, improves fail safe and reliability.

Description of drawings

Fig. 1 is topological structure schematic diagram of the present utility model.

Schematic diagram when Fig. 2 is active the opening of the positive half cycle of topological structure of the present utility model.

Schematic diagram when Fig. 3 is the passive afterflow of the positive half cycle of topological structure of the present utility model.

Schematic diagram when Fig. 4 is active the opening of topological structure negative half period of the present utility model.

Schematic diagram when Fig. 5 is the passive afterflow of topological structure negative half period of the present utility model.

Embodiment

As shown in Figure 1, the utility model comprises the loop with afterflow and control action, and the loop comprises bus capacitor C, controlled switch T1, T2, T3, T4, T5, T6, the first filter inductance L1, the second filtering L2 and EMC filter;

T1～T6 is IGBT single tube or MOSFET.

Bus capacitor C is in parallel with DC power supply PV, and T1, T3, T5 connect successively, is connected in parallel on the two ends of bus capacitor C simultaneously, and described T2 is in parallel with T1, and T4, T6 are connected in series, and is connected in parallel on the two ends of T3, T5 simultaneously; T3 connects the pin of T5, also link to each other with the first filter inductance L1, the first filter inductance L1 connects a pin of EMC filter, and another pin of described EMC filter connects the pin that T4 links to each other with T6 by the second filter inductance L2, and circuit is connected to the grid by the EMC filter of back.

The course of work of the present utility model is:

This topological structure is at the positive half cycle of line voltage, and T2, T4, T5 are in closed condition, the T3 conducting, and T1, T6 are with SPWM control method control switch.

As shown in Figure 2, in that T1, T6 are active when opening, electric current presses that arrow signal direction flows along dotted line among Fig. 2, is flowed out by the positive pole of PV, through T1, T3, the first filter inductance L1, EMC filter, electrical network, the second filter inductance L2, T6, flows back to the PV negative pole;

As shown in Figure 3, during passive afterflow, T1, T6 close, and the energy storage in the inductance is pressed the direction of arrow signal among Fig. 3 along dotted line, the T4 that flows through, T3 afterflow.

This topological structure is at the line voltage negative half period, and T1, T3, T6 are in closed condition, the T4 conducting, and T2, T5 are with SPWM control method control switch.

As shown in Figure 4, in that T2, T5 are active when opening, electric current presses that arrow signal direction flows along dotted line among Fig. 4, and electric current is flowed out by the positive pole of PV, through T2, T4, the second filter inductance L2, EMC filter, electrical network, the first filter inductance L1, T5, flows back to the PV negative pole;

As shown in Figure 5, during passive afterflow, T2, T5 close, and the energy storage in the inductance is pressed the direction of arrow signal among Fig. 5 along dotted line, flows through T3, T4 afterflow.

Only be a kind of of control algolithm below, this topological circuit can have different software control algorithms.

More than an embodiment of the present utility model is had been described in detail, but described content only is preferred embodiment of the present utility model, can not be considered to for limiting practical range of the present utility model.All equalizations of doing according to the utility model application range change and improve etc., all should still belong within the patent covering scope of the present utility model.

Claims

1. efficient low-leakage current inverter topology, it is characterized in that: comprise the loop with afterflow and control action, described loop comprises bus capacitor C, first to the 6th controlled switch (T1, T2, T3, T4, T5, T6), first, second filter inductance L1, L2 and filter;

2. topological structure according to claim 1 is characterized in that: described controlled switch can be one or more the combination in IGBT, MOSFET, the silicon controlled rectifier.

3. topological structure according to claim 1, it is characterized in that: described filter is the EMC filter.