CN112910229B - High-order self-energy-taking power supply design method of IGCT converter module - Google Patents

Abstract

The invention discloses a method for designing a high-level self-energy-taking power supply of an IGCT converter module, which comprises the following steps: determining a power supply form in the module; determining a power supply isolation voltage; determining the output power of the power supply; and designing a power supply at a control side according to the determined power supply form, power supply isolation voltage and power supply output power in the module. By the method, on one hand, when the voltage UDC is applied to the direct-current capacitor, the voltage difference value between the weak current side and any part of the module is not greater than UDC/2, partial discharge is avoided, the insulation interval is reduced, and the compactness of the module is promoted; on the other hand, the number of isolated output circuits of the power supply is reduced, which contributes to the design of low cost, high reliability and miniaturization of the power supply.

Description

Design method of high-level self-energy harvesting power supply for IGCT converter module

technical field

The invention belongs to the field of power supply design, and in particular relates to a high-level self-energy-capturing power supply design method for an IGCT converter module.

Background technique

In the converter scenario, due to the complex electromagnetic environment, all the weak current equipment of the module (such as device drivers, ground floors, sensors, etc.) need to be connected to a fixed potential in the module (such as the negative pole of the DC capacitor, the neutral point of the DC capacitor) as its Reference ground (hereinafter referred to as ground), and then add electromagnetic interference shielding and protection.

In ICGT converter modules (such as half-bridge modules, full-bridge modules, and diode-clamped three-level modules), since the IGCT adopts an integrated gate drive design, its weak and strong current sides have complex electrical connections, and there is no isolation , will introduce the potential of the strong current side into the weak current side, and when the weak current side is powered and grounded, it may cause potential conflicts and cause short circuits.

Contents of the invention

Aiming at the above-mentioned technical problems in the related art, the present invention proposes a high-level self-energy-capturing power supply design method for an IGCT converter module, which can overcome the above-mentioned shortcomings of the prior art.

For realizing above-mentioned technical purpose, technical scheme of the present invention is realized like this:

A high-level self-energy-capturing power supply design method for an IGCT converter module, the method comprising: determining the form of power supply in the module; determining the isolation voltage of the power supply; determining the output power of the power supply; according to the determined form of power supply in the module, the isolation voltage of the power supply, The output power of the power supply is designed for other sources on the control side.

Further, the determining the power supply form in the module includes: determining the power supply form in the module according to the module voltage level and the grounding scheme;

Said determining the power isolation voltage includes:

Determine the power isolation voltage according to the rated voltage of the module;

The determination of the output power of the power supply includes:

The output power of the power supply is determined according to the drive power of each IGCT, where the IGCT is a press-packed integrated gate commutated thyristor.

Further, the determination of the power supply form in the module includes: scheme a and/or scheme b; the scheme a provides an N+1 isolated power supply scheme for the power supply, where N represents the number of IGCTs in the module, and for the half-bridge module : N=2, for the full bridge module: N=4; the scheme b provides an N-way isolated power supply scheme for the power supply.

Further, the structural circuit of the scheme a includes: a power supply, the power supply respectively supplies power for the driver in IGCTT1, the driver in IGCTT2, and the control measurement equipment; the IGCTT1 is connected in parallel with the diode D1; the IGCTT2 is connected with the diode D1 D2 is connected in parallel; the parallel connection part of the IGCTT1 and the diode D1 is connected in series with the parallel connection part of the IGCTT2 and the diode D2; the parallel connection part of the IGCTT1 and the diode D1 is respectively connected to one end of the diode Ds and the reactor Ls; the diode Ds One end of the resistor Rs and one end of the capacitor Cs are respectively connected; the resistor Rs is respectively connected with one end of the reactor Ls, the resistor RM, and the capacitor C0; the reactor Ls is respectively connected with one end of the resistor RM and the capacitor C0 connected; one end of the resistor RM is connected to one end of the capacitor C0 and the resistor RN respectively; one end connected to the resistor RM and the resistor RN is grounded; one end of the parallel part of the IGCTT2 and the diode D2 is respectively connected to the capacitor Cs, One end of the capacitor C0 and the resistor RN are connected; one end of the resistor Rs is connected with one end of the capacitor Cs.

Further, the structural circuit of the scheme b includes: a power supply, which supplies power to the drivers in IGCTT1 and IGCTT2 respectively; one end of the power supply is connected to a DC/DC isolated power supply, and the DC/DC The DC isolated power supply supplies power for the control and measurement equipment; the IGCTT1 is connected in parallel with the diode D1; the IGCTT2 is connected in parallel with the diode D2; the parallel part of the IGCTT1 and the diode D1 is connected in series with the parallel part of the IGCTT2 and the diode D2; the IGCTT1 and the parallel part of the diode D2 are connected in series; The parallel part of the diode D1 is respectively connected to one end of the diode Ds and the reactor Ls; one end of the diode Ds is respectively connected to one end of the resistor Rs and the capacitor Cs; the resistor Rs is respectively connected to one end of the reactor Ls and the capacitor C0 One end is connected; the reactor Ls is connected to one end of the capacitor C0; one end of the capacitor C0 is grounded; one end of the parallel connection part of the IGCTT2 and the diode D2 is respectively connected to one end of the capacitor Cs and the capacitor C0; One end of the resistor Rs is connected to one end of the capacitor Cs; the IGCTT2, one end of the parallel connection part of the diode D2, and one end of the capacitor Cs are grounded.

Further, the voltage of the structural circuit of the scheme b includes the isolation voltage of the DC/DC isolated power supply and the voltage of the IGCT drive circuit; the isolation voltage of the DC/DC isolated power supply is greater than the voltage of the IGCT drive circuit.

Further, in the determination of the power supply isolation voltage, the isolated power supply voltage for a single module is twice the rated voltage.

Further, the determination of the output power of the power supply includes: according to the operating voltage, current, and frequency of the converter, by consulting the IGCT data sheet, confirming the driving power driven by each IGCT in the module; calculating the power supply according to the confirmed driving power The output power of the power supply.

Beneficial effects of the present invention: through this method, on the one hand, when the voltage U _DC is applied to the DC capacitor, the voltage difference between the weak current side and any part of the module is not greater than U _DC /2, which is beneficial to avoid partial discharge and reduce the insulation interval. It promotes the compactness of the module; on the other hand, it reduces the number of isolated output channels of the power supply, which contributes to the low-cost, high-reliability, and miniaturized design of the power supply.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 shows a flow chart of a high-level self-energy-capturing power supply design method of an IGCT converter module according to an embodiment of the present invention;

FIG. 2 shows a schematic circuit diagram corresponding to solution a according to an embodiment of the present invention;

FIG. 3 shows a schematic circuit diagram corresponding to solution b according to an embodiment of the present invention;

Fig. 4 shows a flowchart of determining the output power of a power supply according to an embodiment of the present invention.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments It is a part of embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

As shown in Figure 1, a high-level self-energy-capturing power supply design method for an IGCT converter module, the method includes:

Step S1: Determine the power supply form in the module;

Step S2: Determine the power isolation voltage;

Step S3: Determine the output power of the power supply;

Step S4: According to the determined energy source of the power supply, the power supply form in the module, the isolation voltage of the power supply, and the output power of the power supply, design the power supply of the control side.

In some embodiments of the present invention, the determination of the power supply form in the module includes: determining the power supply form in the module according to the module voltage level and the grounding scheme; the determination of the power isolation voltage includes: determining the power isolation voltage according to the rated voltage of the module Voltage; said determining the output power of the power supply includes: determining the output power of the power supply according to the driving power of each IGCT, wherein the IGCT is a press-packed integrated gate commutated thyristor.

In some embodiments of the present invention, the determination of the power supply form in the module includes: scheme a and/or scheme b, wherein, a and b represent the distinguishing symbols of the scheme name; the scheme a provides N+1 for the power supply One-way isolated power supply scheme, where N represents the number of IGCT devices in the module; the scheme b provides an N+-way isolated power supply scheme for the power supply.

In some embodiments of the present invention, as shown in FIG. 2 , the structural circuit of the scheme a includes: a power supply, the power supply is respectively for IGCTT ₁ , IGCTT ₂ , and control and measurement equipment; the IGCTT ₁ and The diode D ₁ is connected in parallel; the IGCTT ₂ is connected in parallel with the diode D ₂ ; the parallel connection part of the IGCTT ₁ and the diode D ₁ is connected in series with the parallel connection part of the IGCTT ₂ and the diode D ₂ ; the IGCTT ₁ and the diode D ₁ are connected in series. The parallel part is respectively connected with one end of diode D _s and reactor L _s ; one end of said diode D _s is respectively connected with one end of resistance R _s and capacitor C _s ; said resistance R _s is respectively connected with said reactor L _s , One end of the resistor R _M and the capacitor C ₀ is connected; the reactor L _s is connected with one end of the resistor R _M and the capacitor C ₀ respectively; one end of the resistor R _M is respectively connected with the capacitor C ₀ and the resistor R _N One end of the resistor R _M and the resistor R _N are connected to the ground; one end of the IGCTT ₂ and the parallel part of the diode D ₂ are respectively connected to one end of the capacitor C _s , capacitor C ₀ , and resistor R _N ; One end of the resistor R _s is connected to one end of the capacitor C _s . IGCTT ₁ and IGCTT ₂ include drivers.

In some embodiments of the present invention, as shown in FIG. 3 , the structural circuit of the scheme b includes: a power supply, which supplies power for the drive in IGCTT ₁ and the drive in IGCTT ₂ respectively; the power supply One end of the power supply is connected to a DC/DC isolated power supply, and the DC/DC isolated power supply supplies power for the control and measurement equipment; the IGCTT ₁ is connected in parallel with the diode D ₁ ; the IGCTT ₂ is connected in parallel with the diode D ₂ ; the IGCTT ₁ , the diode D The parallel part of ₁ is connected in series with the parallel part of the IGCTT ₂ and the diode D ₂ ; the parallel part of the IGCTT ₁ and the diode D ₁ is respectively connected with one end of the diode D _s and the reactor L _s ; the diode D _s One end is connected to one end of the resistor R _s and the capacitor C _s respectively; the resistor R _s is connected to one end of the reactor L _s and the capacitor C ₀ respectively; the reactor L _s is connected to one end of the capacitor C ₀ ; One end of the capacitor C ₀ is grounded; one end of the IGCTT ₂ and the parallel part of the diode D ₂ are respectively connected to one end of the capacitor C _s and the capacitor C ₀ ; one end of the resistor R _s is connected to the capacitor C _s One end of the IGCTT ₂ , one end of the parallel connection part of the diode D ₂ , and one end of the capacitor C _s are grounded.

In some embodiments of the present invention, the resistance values of the resistors R _M and R _N are equal.

In some embodiments of the present invention, the voltage of the structural circuit of the scheme b includes the isolation voltage of the DC/DC isolated power supply and the voltage of the IGCT drive circuit; the isolation voltage of the DC/DC isolated power supply is greater than that of the IGCT drive circuit voltage.

In some embodiments of the present invention, in determining the power supply isolation voltage, the isolated power supply voltage for a single module is twice the rated voltage. When an external independent power supply is used, the voltage difference between the power supply circuits of each module is greater than the isolation capability of the voltage difference between the modules.

As shown in Figure 4, step S4 includes:

Step S401: According to the operating voltage, current, and frequency of the converter, check the IGCT data sheet to confirm the driving power of each IGCT driver in the module;

Step S402: Calculate the output power of the power supply according to the confirmed driving power.

The present invention proposes two power supply design schemes for the control side of the IGCT converter module, and realizes power supply and grounding without mutual interference while using the most simplified power supply equipment. N represents the number of IGCTs in the module, for example, N=2 for half-bridge modules, N=4 for full-bridge modules, and N=12 for diode-clamped three-phase three-level converters. The power supply may be a high-level self-powered power supply, an independent power supply, or the like.

(1) Determine the power supply form in the module according to the module voltage level and grounding scheme

a. The power supply provides N+1 isolated power supply solutions. The isolation voltage level is greater than the maximum possible DC voltage of the module. N channels are respectively supplied to drive N IGCTs, and one channel is supplied to control and measure equipment such as floors and sensors. Under this scheme, the method of connecting the DC capacitor in parallel with the voltage dividing resistor can be used to lead out the DC neutral point as the weak current reference ground (as shown in Figure 2).

b. The power supply provides an N-way isolated power supply solution. The isolation voltage level is greater than the maximum possible DC voltage of the module. The N channels respectively supply N IGCTs for driving. Connect a DC/DC isolated power supply in parallel to the drive power supply cable of any IGCT that is directly connected to the DC negative busbar of the module, and use this power supply to supply power for control and measurement equipment such as floors and sensors. The isolation voltage of the DC/DC isolated power supply is greater than the maximum voltage (usually tens of volts) that may occur in the IGCT drive circuit. Under this scheme, the DC negative busbar of the module can be used as the weak current reference ground (as shown in Figure 3). Due to the low isolation voltage and low power (the power of the control and measurement equipment is usually less than 10 watts), the volume and cost of the required DC/DC isolation power supply are negligible compared to the entire module.

(2) Determine the power isolation voltage according to the rated voltage of the module

For each isolated power supply of a single module, its isolation voltage should not be less than the highest possible voltage of the module, usually twice the rated voltage or consistent with the off-state repetitive peak voltage of the device. For the form of external independent power supply, the power supply circuits of each module must also have an isolation capability greater than the maximum voltage difference that may occur between modules.

(3) Determine the output power of the power supply according to the driving power of each IGCT

According to the operating voltage, current, and frequency of the converter, by consulting the IGCT data sheet, confirm the maximum driving power of each IGCT in the module, and calculate the output power of the power supply after leaving a certain margin.

(4) According to the aforementioned indicators, design the power supply.

In a specific embodiment of the present invention, the MMC full-bridge module applied to high-voltage collection of offshore wind power is based on ABB's 5SHY 42L6500 IGCT device, with a rated voltage of 3000V, a rated current of 1000A, and a rated frequency of 50Hz. The rated voltage of the module is high. In order to facilitate the insulation design, the neutral point grounding scheme should be adopted. Therefore, scheme a is used to design the power supply, with 5 isolated outputs, 4 supplying 4 IGCTs, and 1 supplying the module control and protection equipment. Isolation voltage is consistent with IGCT, selected as 6500V. Check the manual, IGCT device drive power is 17W at 50Hz, 1000A, after leaving a certain margin, the rated power of the four IGCT drive power supply channels is 25W, and the rated power of the module control and protection equipment power supply channel is 15W.

In a specific embodiment of the present invention, the MMC half-bridge module applied to 10kV STATCOM is based on the CAC5000-45 Plus IGCT device of CRRC Zhuzhou Times Semiconductor Co., Ltd., the rated voltage of the module is 2000V, the rated current is 2000A, and the rated frequency is 250Hz. The rated voltage of the module is moderate, and the negative busbar grounding scheme can be adopted, so the scheme b is used to design the power supply. 2 isolated outputs, respectively supplying 2 IGCTs, the T2 tube IGCT power supply is supplied to the module control and protection equipment after a first-level DC/DC isolation. The isolation voltage between channels is the same as that of IGCT, and is selected as 4500V. In addition, there should be a 10kV isolation voltage level between the input side of the external power supply and each output channel. Check the manual, 250Hz, 2000A IGCT device drive power 67W, after leaving a certain margin, the rated power of the two power supply channels is 85W.

In the present invention, for scheme a, when the voltage UDC is applied to the _DC capacitor, the voltage difference between the weak current side and any part of the module is not greater than UDC/2, which is beneficial to avoid partial discharge, reduce the insulation interval, and promote the compactness of the module; for Solution b reduces the number of isolated output channels of the power supply, which is helpful for low-cost, high-reliability, and miniaturized design of the power supply. For example, in the half-bridge module, N=2, using this solution can reduce 50% of the isolation output channels.

Through this method, on the one hand, when the voltage U _DC is applied to the DC capacitor, the voltage difference between the weak side and any part of the module is not greater than U _DC /2, which is beneficial to avoid partial discharge, reduce the insulation interval, and promote the compactness of the module; On the one hand, the number of isolated output channels of the power supply is reduced, which contributes to the design of the power supply with low cost, high reliability and miniaturization.

Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that: they can still modify the technical solutions described in the aforementioned embodiments, or perform equivalent replacements for some of the technical features; and these The modification or replacement does not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims (8)

1. A high-order self-energy-obtaining power supply design method of an IGCT converter module is characterized by comprising the following steps:

determining an intra-module power supply form, comprising: scheme a and/or scheme b; the scheme a provides an N + 1-path isolation power supply scheme for a power supply, wherein N represents the number of IGCTs in a module, N paths of power supply are respectively supplied to N IGCT drivers, and 1 path of power supply is supplied to control measurement equipment; under the scheme a, a direct current neutral point is led out in a mode that a direct current capacitor is connected with a divider resistor in parallel and is used as weak current reference ground; the scheme b provides an N-path isolation power supply scheme for the power supply, wherein N paths of power supply are respectively supplied for N IGCT drives, and the direct-current negative bus of the module is used as a weak current reference ground under the scheme b;

determining a power supply isolation voltage;

determining the output power of the power supply;

and designing a power supply at a control side according to the determined power supply form, power supply isolation voltage and power supply output power in the module.

2. The method for designing a high-side self-energized power supply of an IGCT converter module according to claim 1, wherein the determining the power isolation voltage comprises:

determining power supply isolation voltage according to the rated voltage of the module;

the determining the power output power comprises:

and determining the output power of the power supply according to the driving power of each IGCT, wherein the IGCT is a press-fit packaged integrated grid commutation thyristor.

3. The method for designing a high-order self-powered power supply of an IGCT converter module according to claim 1, wherein for a half-bridge module: n =2, for a full bridge module: n =4.

4. An IGCT converter module according to claim 3The design method of the high-order self-energy-taking power supply is characterized in that the structural circuit of the scheme a comprises the following steps: a power supply, which is IGCTT respectively ₁ Medium drive, IGCTT ₂ The drive and the control of the measurement equipment are powered; the IGCTT ₁ And diode D ₁ Parallel connection; the IGCTT ₂ And diode D ₂ Connecting in parallel;

the IGCTT ₁ Diode D ₁ And the IGCTT ₂ Diode D ₂ The parallel parts of (A) are connected in series;

the IGCTT ₁ And the diode D ₁ The parallel parts are respectively connected with a diode D _s Reactor L _s Is connected with one end of the connecting rod; the diode D _s Respectively connected with a resistor R _s Capacitor C _s Is connected with one end of the connecting rod; the resistor R _s Are respectively connected with the reactor L _s Resistance R _M Capacitor C ₀ Is connected with one end of the connecting rod; the reactor L _s Respectively connected with the resistors R _M Capacitor C ₀ Is connected with one end of the connecting rod; the resistor R _M One end of each of the capacitors is connected with the capacitor C ₀ Resistance R _N Is connected with one end of the connecting rod; the resistor R _M And a resistance R _N One end connected with the ground is grounded;

the IGCTT ₂ Diode D ₂ One end of the parallel part of (2) is respectively connected with the capacitor C _s Capacitor C ₀ Resistance R _N Is connected with one end of the connecting rod;

the resistor R _s And said capacitor C _s Is connected at one end.

5. The method for designing the high-level self-energized power supply of the IGCT converter module according to claim 3, wherein the structural circuit of scheme b comprises: a power supply, which is IGCTT respectively ₁ Medium drive, IGCTT ₂ The drive power supply in (1); one end of the power supply is connected with a DC/DC isolation power supply, and the DC/DC isolation power supply supplies power for controlling the measuring equipment;

the IGCTT ₁ And diode D ₁ Parallel connection; the IGCTT ₂ And diode D ₂ Parallel connection;

the IGCTT ₁ Diode D ₁ And the IGCTT ₂ Diode D ₂ The parallel parts of (A) are connected in series;

the IGCTT ₁ And the diode D ₁ The parallel parts are respectively connected with a diode D _s Reactor L _s Is connected with one end of the connecting rod; the diode D _s One end of each of which is connected to a resistor R _s Capacitor C _s Is connected with one end of the connecting rod; the resistance R _s Are respectively connected with the reactor L _s Capacitor C ₀ Is connected with one end of the connecting rod; the reactor L _s And the capacitor C ₀ Is connected with one end of the connecting rod; the capacitor C ₀ One end of the first switch is grounded;

the IGCTT ₂ Diode D ₂ One end of the parallel connection part is respectively connected with the capacitor C _s Capacitor C ₀ Is connected with one end of the connecting rod;

the resistor R _s And said capacitor C _s Is connected with one end of the connecting rod;

the IGCTT ₂ Diode D ₂ One end of the parallel part, a capacitor C _s One end is grounded.

6. The design method for the high-order self-energy-obtaining power supply of the IGCT converter module according to claim 5, wherein the voltages of the structural circuit of the scheme b comprise the isolation voltage of the DC/DC isolation power supply and the voltage of the IGCT driving circuit; the isolation voltage of the DC/DC isolation power supply is greater than the voltage of the IGCT drive circuit.

7. The method as claimed in claim 2, wherein the isolated power supply voltage for a single module in the determined power supply isolation voltage is 2 times of the rated voltage.

8. The method for designing a high-level self-powered power supply of an IGCT converter module according to claim 1, wherein the determining the output power of the power supply comprises:

according to the voltage, current and frequency of the converter, the driving power of each IGCT drive in the module is confirmed by consulting an IGCT data manual;

and calculating the output power of the power supply according to the confirmed driving power.

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