Compensation system for hardware control dead zone error

Abstract

The utility model discloses a hardware control dead zone error compensation system, which comprises a single-phase rectifier bridge, and no bridge arm of the single-phase rectifier bridge respectively comprises a switch tube formed by connecting a triode and a diode in parallel. And the switch tube is connected with a hardware driving chip or a software controller. Dead zone time is detected, the error of the dead zone time is calculated, and then compensation is carried out; the dead time refers to that in the actual control process, in order to protect the switching tubes, driving of the two tubes needs to be cut off for a period of time at the moment when the upper tube and the lower tube of the same bridge arm are alternate, and the period of time is called the dead time. The hardware control is that a driving chip is used for enabling PWM waveform delay to rise; according to the software control, a controller directly sends out PWM waves containing dead zones. Dead zone time is not influenced by element precision, temperature drift and the like, and control is accurate.

Description

TECHNICAL FIELD

[0001] The utility model relates to a bridge circuit control technology, especially a hardware control dead time error compensation system. BACKGROUND

[0002] At present, in power electronic products, generally uses bridge circuit and power electronic device (such as thyristor, MOSFET, IGBT etc.) to transform and control electric energy.

[0003] Figure 1 As shown, it is the single-phase rectifier bridge controlled by IGBT, when triggering in certain order, can realize the control to voltage and current.In actual control process, due to improper control or the existence of on-off delay of switch tube, the upper and lower tubes of same bridge arm are simultaneously turned on, then equivalent to directly short-circuiting power supply, thereby burning switch tube.In order to protect switch tube, needs to cut off the drive of two tubes for a period of time when the upper and lower tubes are alternated, this period of time is also called dead time.

[0004] Prior art and defects:

[0005] When using hardware control dead time, dead time is adjusted through resistance or capacitance, and dead time may not be accurate due to the influence of element precision and temperature drift.

[0006] Therefore, the utility model is provided. Utility model content

[0007] The utility model aims at providing a hardware control dead time error compensation system to solve the above technical problems in prior art.

[0008] The utility model aims at realizing the following technical scheme:

[0009] The hardware control dead time error compensation system of the utility model, including single-phase rectifier bridge, the inductive and input resistance of single-phase rectifier bridge's AC input end are connected in series, and the output resistance and capacitor of output end are connected in parallel;

[0010] The bridge arm of single-phase rectifier bridge does not include the switch tube that is composed of the parallel connection of triode and diode.

[0011] Compared with prior art, the hardware control dead time error compensation system provided by the utility model, dead time is not influenced by element precision and temperature drift, and is accurate. DRAWINGS

[0012] Figure 1 It is the schematic diagram of single-phase rectifier bridge in the utility model embodiment;

[0013] Figure 2The hardware control dead zone error compensation system flow chart in the embodiment of the utility model;

[0014] Figure 3 The dead zone time calculation schematic diagram in the embodiment of the utility model. DETAILED DESCRIPTION

[0015] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model; obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments, which does not constitute a limitation to the utility model. Based on the embodiments of the utility model, all other embodiments obtained by the ordinary skilled in the art without making creative efforts belong to the protection scope of the utility model.

[0016] Firstly, the terms possibly used in the present text are explained as follows:

[0017] The term "and / or" means either one or both, for example, X and / or Y means three cases including "X", "Y" or "X and Y".

[0018] The terms "include", "contain", "have", "possess" or other similar semantic descriptions should be interpreted as non-exclusive inclusion. For example: including a technical feature element (such as raw materials, components, ingredients, carriers, dosage forms, materials, sizes, parts, components, mechanisms, devices, steps, processes, methods, reaction conditions, processing conditions, parameters, algorithms, signals, data, products or articles, etc.) should be interpreted as not only including the explicitly listed technical feature element, but also including other technical feature elements not explicitly listed in the art.

[0019] The term "consisting of" means excluding any technical feature element not explicitly listed. If this term is used in the claims, the term will make the claim closed, so that it does not contain technical feature elements other than the explicitly listed technical feature elements, except for conventional impurities related thereto. If the term only appears in a certain clause of the claim, it is only limited to the elements explicitly listed in that clause, and the elements described in other clauses are not excluded from the overall claim.

[0020] The contents not described in detail in the embodiments of the utility model belong to the prior art known to the person skilled in the art. In the embodiments of the utility model, the unspecified conditions are carried out according to the conventional conditions in the art or the conditions recommended by the manufacturer. The reagents or instruments used in the embodiments of the utility model are not marked with the manufacturer, which are all conventional products that can be purchased on the market.

[0021] The hardware control dead zone error compensation system of the utility model, including single -phase rectifier bridge, the single -phase rectifier bridge's AC input end series connection has inductance and input resistance, the output end parallel has output resistance and electric capacity,

[0022] The single -phase rectifier bridge does not have a bridge arm respectively including by triode and diode parallelly connected switch tube.

[0023] The switch tube is connected with hardware drive chip or software controller.

[0024] The hardware control dead zone error compensation system realizes the method of dead zone error compensation, first detects dead zone time and calculates the error of dead zone time, then compensates;

[0025] The dead zone time refers to:

[0026] When IGBT controls single -phase rectifier bridge to trigger in certain order, can realize the control of voltage and current, in actual control process, due to improper control or switch tube itself exists conduction cut-off delay, makes the same bridge arm's upper and lower two tubes conduction simultaneously, then equivalent directly short -circuit power supply, thereby burns switch tube;

[0027] In order to protect switch tube, need in the same bridge arm's upper and lower two tubes alternate moment cut off the drive of two tubes for a period of time, this period of time is called dead zone time.

[0028] The dead zone time is controlled by hardware or software, the hardware control is to use drive chip to make PWM waveform delay rise;The software control is to directly issue the PWM wave containing dead zone in the controller.

[0029] The flow of control includes:

[0030] First, the error Tde of dead zone time is set to 0;

[0031] Then, issue the PWM wave without dead zone, the dead zone is controlled by hardware, then the PWM of hardware output has contained dead zone, carries out dead zone time detection, measures the real dead zone time Tdreal, then combines the set dead zone time Tdref, can obtain the error Tde of dead zone time through calculation = Tdref-Tdreal;

[0032] If the error is less than error limit ε at this time, it is indicated that the error is small, then directly output, end the flow;

[0033] If the error is greater than error limit ε at this time, it is indicated that the error is large, then reissue PWM through software, and control dead zone time Td=Tde.

[0034] The dead zone time detection method is:

[0035] The dead time is calculated by the difference between the turn-off time of one tube and the turn-on time of another tube of the same bridge arm. Assuming that the turn-off time is Toff and the turn-on time is Ton, the dead time Td=(Toff-Ton) / 2.

[0036] The turn-on time and the turn-off time are realized by capturing rising and falling edges by the processor and cooperating with internal counters.

[0037] As can be seen from the above, the compensation system for hardware control of dead time error provided in the embodiments of the present application first detects the dead time and calculates the error of the dead time, and then compensates through software. The dead time is not affected by element precision and temperature drift, and the control is accurate.

[0038] In order to more clearly show the technical solutions provided by the present application and the technical effects generated, the following will describe the compensation system for hardware control of dead time error provided in the embodiments of the present application in detail with specific embodiments.

[0039] Embodiment 1, as shown in Figures 1 to 3 .

[0040] The flow of control is shown in Figure 2 .

[0041] When the first step is executed, Tde is set to 0, and then a PWM wave without dead time is sent. Since the dead time is controlled by hardware, the PWM output by the hardware already contains the dead time. The dead time detection is performed on it, the real dead time Tdreal can be measured, and then the error Tde=Tdref-Tdreal of the dead time is calculated by combining the set dead time Tdref. If the error is less than the error limit ε at this time, it means that the error is already small, and then the flow is directly output and ended. If the error is greater than the error limit ε at this time, it means that the error is large, and then the PWM is sent again through software, and Td=Tde is controlled.

[0042] Submodule description:

[0043] Dead time detection

[0044] The dead time is calculated by the difference between the turn-off time of one tube and the turn-on time of another tube of the same bridge arm. Assuming that the turn-off time is Toff and the turn-on time is Ton, the dead time Td=(Toff-Ton) / 2.

[0045] The turn-on time and the turn-off time can be realized by capturing rising and falling edges by the processor and cooperating with internal counters, and the specific method is not limited.

[0046] The above merely describes a preferred specific implementation of the present application, but the scope of protection of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present application, which should be encompassed within the scope of protection of the present application. Therefore, the scope of protection of the present application should be subject to the scope of protection of the claims. The information disclosed in the background section of the present application is merely intended to deepen the understanding of the overall background technology of the present application, and should not be regarded as acknowledging or implying in any form that the information constitutes the prior art known to those skilled in the art.

Claims

1. A hardware-controlled dead-zone error compensation system, characterized in that, It includes a single-phase rectifier bridge, wherein an inductor and an input resistor are connected in series at the AC input terminal of the single-phase rectifier bridge, and an output resistor and a capacitor are connected in parallel at the output terminal; Each arm of the single-phase rectifier bridge includes a switching transistor composed of a transistor and a diode connected in parallel. The switching transistor is connected to a hardware driver chip or a software controller.

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