Single-phase half-control diode clamping bridge arm hybrid two-level rectifier

Abstract

A single-phase half-control diode clamping bridge arm hybrid two-level rectifier comprises an alternating current power supply vin, uncontrolled diode rectifier bridge arms D1-D4, diodes D5-D10, an inductor L, an inductor L1, an inductor L2, a switch tube S1, a switch tube S2, a switch tube Sa, a capacitor C and a resistor R. The diodes D5-D8 and the power switch tubes S1 and S2 form a diode clamping bidirectional switch. According to the hybrid rectifier, the power ratio of the rectifier can be flexibly distributed, so that the circuit has the characteristics of high power factor, low harmonic distortion rate and high reliability; compared with a traditional two-level converter, the single-phase half-control diode clamping bridge arm hybrid two-level rectifier has the advantages that load power is borne by two rectifiers, the quota and loss of devices are effectively reduced, and the efficiency and power density of a circuit are greatly improved.

Description

Technical Field

[0001] The invention relates to a two-level rectifier, in particular to a single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier. Background Art

[0002] In modern power electronics technology, rectifiers, as important devices connecting AC power and DC loads, have been widely used in various electrical equipment and systems. Traditional fully controlled rectifiers, such as thyristors (SCRs) and insulated gate bipolar transistors (IGBTs), can achieve precise output control, but their control circuits are relatively complex. In addition, traditional diode rectifiers have shortcomings in rectification efficiency and power factor. In order to solve these problems, researchers began to explore the application of semi-controlled technology, especially combining diodes with components such as thyristors to achieve higher performance and flexibility.

[0003] With the increasing requirements for power quality and energy efficiency, multiple adjustable power conversion paths are formed by rationally configuring half-controlled diodes and controllable elements. This hybrid structure can not only improve the working efficiency of the rectifier, but also effectively reduce harmonics and power loss. In practical applications, the rectifier can achieve precise control of the load waveform, improve power quality, and meet the needs of various loads, especially in the access of photovoltaic power generation, wind power generation and other renewable energy sources. Summary of the invention

[0004] The present invention proposes a single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier, which combines the characteristics of a half-controlled diode and a controllable element, so that a high conversion efficiency can be maintained even under low load conditions. At the same time, the rectifier can respond quickly when the load changes and maintain a stable DC output voltage, which is suitable for application scenarios with high requirements for dynamic performance.

[0005] The technical solution adopted by the present invention is:

[0006] A single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier, the rectifier comprises:

[0007] Uncontrolled diode rectifier bridge arm D 1 ~D 4 、Diode D 5 ~D 10 , inductance L, inductance L 1 、Inductance L 2 , switch tube S 1 , switch tube S 2 , switch tube S a , capacitor C, resistor R;

[0008] AC power supplyv in One side of the ground, AC power supply vin The other side is connected to diode D 1 The anode of diode D 2 The cathode of and one end of the inductor L;

[0009] The other end of the inductor L is connected to the diode D 5 The anode of diode D 6 The cathode of , whose connection node constitutes node a;

[0010] Diode D 1 The cathode of diode D 3 The cathode of each is connected to the inductor L 1 One end of the diode D 2 The anode of diode D 4 The anodes of the 2 one end of

[0011] Diode D 5 The cathode of the diode D 7 Anode, switch tube S 1 The drain of diode D 6 The anodes of the diodes D 8 The cathode of the switch tube S 2 The source of

[0012] Switching tube S 1 The source of the switch tube S 2 The drain terminals are connected to the AC power supply V in The other side of is connected to the ground, and its connection node constitutes node n;

[0013] Inductance L 1 The other end is connected to the diode D 9 Anode, switch tube S a The drain;

[0014] Diode D 7 The cathode of the diode D 9 The cathode of, one end of capacitor C, one end of load R;

[0015] Inductance L 2 The other end is connected to the diode D 10 The cathode of the switch tube S a The source of

[0016] Diode D 8 The anodes of the diodes D 10 anode, the other end of capacitor C, and the other end of load R.

[0017] The diode D 1 ~D 4The connection forms an uncontrolled rectifier circuit.

[0018] The diode D 5 ~D 8 , power switch tube S 1 , S 2 The connection forms a diode clamped bidirectional switch.

[0019] The diode D 5 , D 6 A set of diode clamping bridge arms is formed.

[0020] Single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier, including 4 working modes:

[0021] Mode 1: Switching tube S 1 The switch tube S is turned on. 2 Turn off, current flows through the inductor L, diode D 5 , switch tube S 1 After returning to the AC power supply v in ; At this time, the AC power supply v in The inductor L is charged to store energy, the inductor current increases linearly, the load R is powered by the capacitor C, and the voltage U an =0;

[0022] Mode 2: Switching tube S 1 , S 2 Turn off, current flows through the inductor L, diode D 5 , diode D 7 , capacitor C, diode D 8 , switch tube S 2 The freewheeling diode returns to the AC power supply v in ; At this time, the inductance L and the AC power supply v in At the same time, the capacitor C is charged, the inductor current decreases linearly, and the voltage U an =+v o ;

[0023] Mode 3: Switching tube S 2 The switch tube S is turned on. 1 Turn off, current flows through the switch tube S 2 , diode D 6 , inductor L returns to the AC power supply v in ; At this time, the AC power supply v in The inductor L is charged to store energy, the inductor current increases linearly, the load R is powered by the capacitor C, and the voltage U an =0;

[0024] Mode 4: Switching tube S 1 , S 2 Turn off, current flows through the switch tube S 1 The freewheeling diode, diode D7 , capacitor C, diode D 8 , diode D 6 , inductor L returns to the AC power supply v in ; At this time, the AC power supply v in As the inductor L charges the capacitor C, the inductor current decreases linearly and the voltage U an =-v o .

[0025] Use diode D 9 , D 10 It allows the current of capacitor C to flow only to load R, ensuring single-phase power flow; at the same time, it acts as a boost clamping diode during mode switching.

[0026] In the 4 working modes, the capacitor voltage v c =v o .

[0027] The present invention provides a single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier, and the technical effects are as follows:

[0028] 1) The present invention discloses a single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier. Compared with the traditional two-level converter, the load power is borne by two rectifiers, which effectively reduces the rating and loss of the device, greatly improves the efficiency and power density of the circuit, and is suitable for application scenarios with high requirements on dynamic performance.

[0029] 2) The present invention is a single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier. The diode clamping structure can effectively limit the impact of overvoltage on the circuit, protect downstream components from impact, and improve the safety of the system. At the same time, it can reduce the need for complex protection circuits, thereby simplifying the design and improving the reliability and maintainability of the system.

[0030] 3) The present invention is a single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier, which adopts a single-phase half-controlled diode clamped bridge arm hybrid two-level structure, can ignore the circuit circulation problem, flexibly allocate the power ratio of the rectifier, so that the circuit meets the characteristics of high power factor, low harmonic distortion rate, and high reliability. At the same time, it combines the characteristics of half-controlled diodes and controllable elements, so that a high conversion efficiency can be maintained under low load conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0032] Figure 1 The schematic diagram of a single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier circuit.

[0033] Figure 2Schematic diagram of the current path of a single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier in operating mode 1.

[0034] Figure 3 A schematic diagram of the current path of a single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier in operating mode 2.

[0035] Figure 4 A schematic diagram of the current path of a single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier operating mode 3.

[0036] Figure 5 A schematic diagram of the current path of a single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier operating mode 4.

[0037] Figure 6 The input voltage v is a single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier in 、Current i 1 Waveform graph.

[0038] Figure 7 The input voltage v is a single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier in 、Current i 2 Waveform graph.

[0039] Figure 8 The total input voltage v of a single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier is in 、Current i in Waveform graph.

[0040] Fig. 9 The bridge arm voltage U is a single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier circuit an Waveform graph.

[0041] Fig.10 The voltage across the load R of a single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier is v o Waveform graph.

[0042] Fig.11 The output DC voltage v is a single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier when the load R is halved. o Waveform graph. DETAILED DESCRIPTION

[0043] like Figure 1 As shown, a single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier, the rectifier comprises:

[0044] Uncontrolled diode rectifier bridge arm D 1 ~D 4 、Diode D 5 ~D10 , inductance L, inductance L 1 、Inductance L 2 , switch tube S 1 , switch tube S 2 , switch tube S a , capacitor C, resistor R;

[0045] AC power supplyv in One side of the ground, AC power supply v in The other side is connected to diode D 1 The anode of diode D 2 The cathode of and one end of the inductor L;

[0046] The other end of the inductor L is connected to the diode D 5 The anode of diode D 6 The cathode of , whose connection node constitutes node a;

[0047] Diode D 1 The cathode of diode D 3 The cathode of each is connected to the inductor L 1 One end of the diode D 2 The anode of diode D 4 The anodes of the 2 one end of

[0048] Diode D 5 The cathode of the diode D 7 Anode, switch tube S 1 The drain of diode D 6 The anodes of the diodes D 8 The cathode of the switch tube S 2 The source of

[0049] Switching tube S 1 The source of the switch tube S 2 The drain terminals are connected to the AC power supply V in The other side of is connected to the ground, and its connection node constitutes node n;

[0050] Inductance L 1 The other end is connected to the diode D 9 Anode, switch tube S a The drain;

[0051] Diode D 7 The cathode of the diode D 9 The cathode of, one end of capacitor C, one end of load R;

[0052] Inductance L 2 The other end is connected to the diode D 10 The cathode of the switch tube Sa The source of

[0053] Diode D 8 The anodes of the diodes D 10 anode, the other end of capacitor C, and the other end of load R.

[0054] The diode D 1 ~D 4 The connection forms an uncontrolled rectifier circuit.

[0055] The diode D 5 ~D 8 , power switch tube S 1 , S 2 The connection forms a diode clamped bidirectional switch.

[0056] The diode D 5 , D 6 A set of diode clamping bridge arms is formed.

[0057] Single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier, including 4 working modes:

[0058] Mode 1: Switching tube S 1 The switch tube S is turned on. 2 Turn off, current flows through the inductor L, diode D 5 , switch tube S 1 After returning to the AC power supply v in ; At this time, the AC power supply v in The inductor L is charged to store energy, the inductor current increases linearly, the load R is powered by the capacitor C, and the voltage U an =0;

[0059] Mode 2: Switching tube S 1 , S 2 Turn off, current flows through the inductor L, diode D 5 , diode D 7 , capacitor C, diode D 8 , switch tube S 2 The freewheeling diode returns to the AC power supply v in ; At this time, the inductance L and the AC power supply v in At the same time, the capacitor C is charged, the inductor current decreases linearly, and the voltage U an =+v o ;

[0060] Mode 3: Switching tube S 2 The switch tube S is turned on. 1 Turn off, current flows through the switch tube S 2 , diode D 6 , inductor L returns to the AC power supply v in; At this time, the AC power supply v in The inductor L is charged to store energy, the inductor current increases linearly, the load R is powered by the capacitor C, and the voltage U an =0;

[0061] Mode 4: Switching tube S 1 , S 2 Turn off, current flows through the switch tube S 1 The freewheeling diode, diode D 7 , capacitor C, diode D 8 , diode D 6 , inductor L returns to the AC power supply v in ; At this time, the AC power supply v in As the inductor L charges the capacitor C, the inductor current decreases linearly and the voltage U an =-v o .

[0062] Use diode D 9 , D 10 It allows the current of capacitor C to flow only to load R, ensuring single-phase power flow; at the same time, it acts as a boost clamping diode during mode switching.

[0063] The specific working principle of a single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier circuit of the present invention is described below. The two-level rectifier has four working modes, among which: the capacitor voltage v c =v o , the specific analysis process is as follows:

[0064] Figure 2 Schematic diagram of the current path in mode 1: switch tube S 1 The switch tube S is turned on. 2 Turn off, current flows through the inductor L, diode D 5 , switch tube S 1 After returning to power supply v in ; At this time, the power supply v in The inductor L is charged to store energy, the inductor current increases linearly, the load R is powered by the capacitor C, and the voltage U an =0;

[0065] Figure 3 Schematic diagram of the current path in mode 2: switch tube S 1 , S 2 Turn off, current flows through the inductor L, diode D 5 , diode D 7 , capacitor C, diode D 8 , switch tube S 2 The freewheeling diode returns to the power supply v in ; At this time, the inductor L and the power supply v inAt the same time, the capacitor C is charged, the inductor current decreases linearly, and the voltage U an =+v o ;

[0066] Figure 4 Schematic diagram of the current path in mode 3: switch tube S 2 The switch tube S is turned on. 1 Turn off, current flows through the switch tube S 2 , diode D 6 , inductor L returns to power supply v in ; At this time, the power supply v in The inductor L is charged to store energy, the inductor current increases linearly, the load R is powered by the capacitor C, and the voltage U an =0;

[0067] Figure 5 Schematic diagram of mode 4 current path: switch tube S 1 , S 2 Turn off, current flows through the switch tube S 1 The freewheeling diode, diode D 7 , capacitor C, diode D 8 , diode D 6 , inductor L returns to power supply v in ; At this time, the power supply v in As the inductor L charges the capacitor C, the inductor current decreases linearly and the voltage U an =-v o .

[0068] Table 1 shows the pulse distribution mode of the rectifier switch tube, the working state of the DC side capacitor and the voltage U an Correspondence table, in which the on and off of the switch tube are represented by "1" and "0" respectively.

[0069] Table 1 Rectifier switch pulse distribution mode, DC side capacitor working state and voltage U an Correspondence table

[0070]

[0071] In order to verify that the single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier of the present invention can realize the two-level function, an experimental verification is carried out under the single-cycle control strategy. The experimental parameters are: AC power frequency is 50Hz, input voltage effective value is 220V, inductance L=50mH, capacitance is 22000uF, switching frequency is 10kHz, boost inductance L 1 =L 2 =2mH, load 50Ω.

[0072] Figure 6 The input voltage v of the single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier isin , input side current i 1 Waveform, input current i 1 Can effectively follow the AC input voltage v in , further reducing the harmonic content of the input side current and realizing the power factor correction function.

[0073] Figure 7 The input voltage v of the single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier is in , input side current i 2 Waveform, input current i 2 Can effectively follow the AC input voltage v in , further reducing the harmonic content of the input side current and realizing the power factor correction function.

[0074] Figure 8 The input voltage v of the single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier is in , total input current i in Waveform, input current i in Can effectively follow the AC input voltage v in , further reducing the harmonic content of the input side current and realizing the power factor correction function.

[0075] Fig. 9 The bridge arm voltage U of the single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier circuit is an From the waveform, we can see that the voltage is alternating between positive and negative and is almost symmetrical. The two-level effect is good, and the experimental verification and theoretical analysis results are consistent. The two-level is the output terminal potential of 0, v o Two types.

[0076] Fig.10 The output DC voltage v of the single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier is o Waveform diagram, the present invention designs a two-level rectifier with input 220V / output 400V, Fig.10 The waveform shows that the voltage v o Stable output.

[0077] Fig.11 The output DC voltage v of the single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier when the load is halved o Waveform, output DC voltage v o The waveform is slightly adjusted at 0.25s to 0.3s and quickly returns to a stable state, indicating that the system has strong dynamic adjustment capability and good anti-disturbance performance.

[0078] The hybrid rectifier can flexibly distribute the power ratio of the rectifier so that the circuit meets the characteristics of high power factor, low harmonic distortion rate and high reliability.

[0079] Compared with a traditional two-level converter, the single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier proposed by the present invention has load power borne by two rectifiers, effectively reducing the rating and loss of the device, and greatly improving the efficiency and power density of the circuit.

Claims

1. A single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier, characterized in that: The rectifier includes: Uncontrolled diode rectifier bridge arms D1 to D4, diodes D5 to D 10 , inductor L, inductor L1, inductor L2, switch tube S1, switch tube S2, switch tube S a , capacitor C, resistor R; AC power supplyv in One side of the ground, AC power supply v in The other side is connected to the anode of the diode D1, the cathode of the diode D2, and one end of the inductor L respectively; The other end of the inductor L is connected to the anode of the diode D5 and the cathode of the diode D6, respectively, and the connection node thereof constitutes a node a; The cathode of the diode D1 and the cathode of the diode D3 are both connected to one end of the inductor L1; the anode of the diode D2 and the anode of the diode D4 are both connected to one end of the inductor L2; The cathode of the diode D5 is connected to the anode of the diode D7 and the drain of the switch tube S1 respectively; the anode of the diode D6 is connected to the cathode of the diode D8 and the source of the switch tube S2 respectively; The source of switch tube S1 and the drain of switch tube S2 are both connected to the AC power supply v in The other side of is connected to the ground, and its connection node constitutes node n; The other end of the inductor L1 is connected to the anode of the diode D9 and the switch tube S a The drain; The cathode of the diode D7 is connected to the cathode of the diode D9, one end of the capacitor C, and one end of the load R respectively; The other end of the inductor L2 is connected to the diode D 10 The cathode of the switch tube S a The source of The anode of diode D8 is connected to diode D 10 anode, the other end of capacitor C, and the other end of load R.

2. According to claim 1, a single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier is characterized in that: The diodes D1 to D4 are connected to form an uncontrolled rectifier circuit.

3. The single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier according to claim 1, characterized in that: The diodes D5 to D8 and the power switch tubes S1 and S2 are connected to form a diode clamped bidirectional switch.

4. The single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier according to claim 1, characterized in that: The diodes D5 and D6 form a set of diode clamping bridge arms.

5. The single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier according to any one of claims 1 to 4, characterized in that: Includes 4 working modes: Mode 1: Switch S1 is turned on, switch S2 is turned off, the current flows through the inductor L, diode D5, and then returns to the AC power supply v after the switch S1 in ; At this time, the AC power supply v in The inductor L is charged to store energy, the inductor current increases linearly, the load R is powered by the capacitor C, and the voltage U an =0; Mode 2: Switches S1 and S2 are turned off, and the current flows through the inductor L, diode D5, diode D7, capacitor C, diode D8, and the freewheeling diode of switch S2 before returning to the AC power supply v in ; At this time, the inductance L and the AC power supply v in At the same time, the capacitor C is charged, the inductor current decreases linearly, and the voltage U an =+v o ; Mode 3: Switch S2 is turned on, switch S1 is turned off, and the current flows through switch S2, diode D6, and inductor L before returning to the AC power supply v in ; At this time, the AC power supply v in The inductor L is charged to store energy, the inductor current increases linearly, the load R is powered by the capacitor C, and the voltage U an =0; Mode 4: Switches S1 and S2 are turned off, and the current flows through the freewheeling diode of switch S1, diode D7, capacitor C, diode D8, diode D6, and inductor L before returning to the AC power supply v in ; At this time, the AC power supply v in As the inductor L charges the capacitor C, the inductor current decreases linearly and the voltage U an =-v o .

6. A single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier according to claim 5, characterized in that: Use diodes D9, D 10 It allows the current of capacitor C to flow only to load R, ensuring single-phase power flow; at the same time, it acts as a boost clamping diode during mode switching.

7. The single-phase half-controlled diode clamped bridge arm hybrid two-level rectifier according to claim 5, characterized in that: In the 4 working modes, the capacitor voltage v c =v o .

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