Pulse width modulation rectifier and control method thereof.

Abstract

The invention provides a pulse width modulation rectifier including a rectifier circuit configured to rectify an alternating current, AC, input voltage; a switching circuit configured to control a direct current, DC, output voltage; and a control unit configured to generate a pulse width modulation, PWM, signal switching the switching circuit on and off; wherein the control unit is configured to generate an injection signal and add the injection signal to the generated PWM signal. The invention further describes a control method of the pulse width modulation rectifier, a computer program, and a computer-readable medium.

Description

6099 / TR 1 TARIFF Pulse width modulated rectifier and its related control. METHOD Related Field The present invention is a pulse width modulated rectifier and its associated control method. It is related to. Previous Technique In power electronics, the conversion of AC power to DC power, and in telecommunications... various equipment, including data centers and industrial motor drives It is a requirement for applications. Traditionally, this conversion was done using rectifiers. This has been achieved. However, these traditional rectifiers often have significant harmonics. This causes degradation and exhibits a poor power factor, resulting in inefficient power. This leads to its use, requiring comprehensive filtering measures. Therefore, a rectifier and a corresponding controller that solves the above problems 20 The method needs to be improved. Brief Description of the Invention Pulse Width Modulation (PWM) rectifiers offer high efficiency and low harmonics. Motor drives for converting AC power to DC power with minimal degradation, renewable energy. It is widely used in applications such as power systems and industrial power supplies. These rectifiers use sinusoidal pulse rectifiers, for example, to control switching devices. It uses Width Modulation (SPWM) techniques to produce a sinusoidal output of an input current. It ensures that the output voltage is regulated. To improve performance, 30 injection signals, such as harmonic components or zero-sequence components, are typically one of the These injection signals are included in the modulation process. These signals form a modulation index. will increase, improve voltage utilization and reduce harmonics in the output voltage waveform. It is designed to reduce degradation. 6099 / TR 2 However, providing an injection signal is done using Intermittent Pulse Width Modulation. When combined with advanced modulation strategies such as (DPWM), it can lead to undesirable effects. It can be switched on. DPWM techniques enable switching of a switching device, such as a power transistor. by selectively reducing its activity during specific intervals of a waveform 5 It is used to minimize switching losses. DPWM reduces losses. and improves system efficiency using an injected signal and intermittent modulation technique. The interaction between them leads to distorted output currents, increased harmonic distortion, and unbalanced power. This can create challenges in its distribution. This invention addresses these problems and Specifically, using injection signals in conjunction with DPWM, PWM rectifiers are 10 A solution is being developed to improve its performance. An injection signal, such as a third harmonic or zero sequence signal, is a reference in PWM. When added to the waveform, it improves voltage handling and reduces harmonic distortion. It modifies the waveform to reduce this. These injection signals are continuously PWM 15 When combined with these schemes, it maximizes DC bus utilization and By optimizing the modulation process to minimize switching stress, an effective It works in this way. However, when Intermittent PWM (DPWM) techniques are used, injection The interaction between the signal and the DPWM technique can cause various problems. In DPWM, the switches in the rectifier reduce the switching frequency at specific intervals. By keeping it inactive (off), switching losses are minimized. This intermittent operation... It creates segments in the waveform, and here the switching activity is entirely... It is being suppressed. Flattening the peaks of the sinusoidal reference or low frequency The injection signal designed to add components interacts with these inactive intervals 25 Problems arise when it comes into play. Therefore, DPWM techniques are generally suitable for bidirectional systems. For bidirectional systems... When the DPWM techniques developed are used in unidirectional systems, distortions occur in the phase currents. This occurs primarily because, for example, a T-type unidirectional Vienna rectifier 30 In this topology, the alternation of the modulation signal of one phase is correlated with the alternation of the current in the same phase. When they are not the same, current flow does not occur. 6099 / TR 3 In conclusion, the advantages of the DPWM technique, such as reducing switching loss, are one-way. Cannot be used in Vienna rectifiers. DPWM is sensitive to switching times. because it is control-based and useful for continuous modulation of the injection signal. However, strategically reducing switching events in DPWM These problems arise because of its interference. Therefore, with this invention, 5 Efficient power that resolves conflicts between injection signals and DPWM techniques. PWM rectifiers provide conversion, reduced harmonics and balanced power distribution. An improved method for monitoring is proposed. To solve the problems mentioned above, the invention includes a pulse width modulated rectifier 10. It is under development and is configured to rectify the input voltage of alternating current, AC. a rectifier circuit configured to control the direct current, DC, output voltage. a switching circuit; and a pulse that switches the said switching circuit on and off. a control unit configured to generate a width modulation, PWM, signal It includes the control unit mentioned here, which will generate an injection signal, and this 15 It is configured to add the injection signal to the generated PWM signal. According to an application of an interrupted pulse width modulation rectifier, the aforementioned When the injection signal is added to the PWM signal by the control unit, the PWM signal... It is configured to control whether its alternation changes or not. 20 According to one application of an interrupted pulse width modulation rectifier, injection If adding this signal to the PWM signal changes the alternation of the PWM signal, then the aforementioned signal... The control unit will also not add the injection signal to the PWM signal and switching. 25 that will use only the PWM signal to switch the circuit. It is being structured. According to an application of an interrupted pulse width modulation rectifier, the control unit Furthermore, when the injection signal is added to the PWM signal, the alternation of the PWM signal... If it doesn't change, it is configured to add the injection signal to the PWM signal. 30 According to an application of an interrupted pulse width modulation rectifier, the aforementioned The control unit ensures that all phases are activated when the injection signal is combined with multiple PWM signals. 6099 / TR 4 If the alternation of the PWM signal does not change, multiple PWM signals for multiple phases. It is configured to generate and add injection signals to the PWM signals. According to one application of an intermittent pulse width modulation rectifier, PWM The switching element of one of the phases of the signals has a phase difference between its first phase and the other phases. If it is closer to driving with the fully open or fully closed, the injection signal The first phase is designed to operate either fully open or fully closed. According to one application of an interrupted pulse width modulation rectifier, injection The signal is transmitted for a period less than 1 / 3 of a period of the aforementioned switching circuit. It is manufactured in such a way that it will not switch during operation. According to an application of an intermittent pulse width modulation rectifier, switching The failure period depends on the AC input voltage and the DC output voltage. According to one application, this is a control related to a pulse width modulated rectifier. The method is being developed: using a rectifier circuit, alternating current, AC, input voltage rectification; direct current, DC, output using a switching circuit voltage control; and switching circuit using a control unit. A pulse width modulated (PWM) signal that switches on and off at a switching frequency of 20 the generation of an injection signal here and the generated PWM signal. It includes the steps for adding it. According to one application, the control of a pulse width modulated rectifier suitable for the invention. a computer program containing instructions that enables it to execute the steps of the method 25 It is being developed. According to one application, by the computer on which the computer program is stored A readable environment is being developed. The invention promotes harmonic performance improvement, reduced switching loss, and voltage peak reduction. It offers advantages such as mitigating pressure points. 6099 / TR Regarding Harmonic Performance Improvement, the phase of the modulation signal alternation... By ensuring consistency with the current, harmonics in the current waveform can be avoided with the current technique. Distortion is significantly reduced, harmonic distortion in unidirectional systems. This is a major problem when using traditional DPWM. Regarding reduced switching loss, traditional DPWM techniques use 1 / 3 of the period. designed to reduce switching losses by not switching throughout. However, the proposed technique optimizes this for unidirectional Vienna Rectifiers. This Although the non-switching period is less than a third in the new technique, it is still... A 10% reduction in switching losses is crucial for improving rectifier efficiency. It provides a reduction. Regarding voltage peak mitigation, the new technique also applies to switching. by helping to reduce drain-source voltage peaks in the components, It is useful in protecting components and increasing the reliability of the system. 15 Brief Description of the Figures Figure 1 illustrates the block diagram of the PWM technique applicable to the invention. Figure 2 shows a three-phase T-type unidirectional NPC T-type Vienna Rectifier circuit. Figure 3 shows a general control block diagram. Figure 4 shows block 25 of a well-known DPWM technique developed for Bidirectional Vienna Rectifiers. It shows the diagram. Figure 5 shows that when the aforementioned DPWM technique is used in a unidirectional Vienna Rectifier, one phase... It shows the current and modulation signal. Figure 6 shows a block diagram of a DPWM technique applicable to the invention. Figure 7 shows the distortions in the current waveform when the method consistent with the invention is applied. This shows that it has been prevented. 6099 / TR 6 Detailed Explanation Harmonic distortion in power systems refers to the presence of frequencies that are multiples of the fundamental frequency. Deviations in the current or voltage from the ideal sinusoidal waveform due to 5 These harmonics represent alternating current (AC) and direct current (DC) waveforms. It occurs during the rectification process where it is converted into a waveform. Traditional The switching process in rectifiers and the characteristics of the components used allow for these additional frequencies. It produces. The presence of harmonics in power systems can cause many problems. Harmonics, This causes an increase in heat in electrical equipment, such as motors, transformers, and This can shorten the lifespan of capacitors. This overheating is caused by additional harmonics. This is caused by current, which in turn affects the conductors and magnetic fields of the devices. It increases losses in their cores. 15 Furthermore, harmonic distortion can lead to electromagnetic interference, which can be sensitive. It can affect the operation of electronic equipment, causing malfunctions or damage. Another critical problem is the decrease in overall system efficiency. Harmonics, in particular... This leads to increased energy consumption by causing additional power losses in conductors and transformers. This can lead to increased operating costs. In addition, the presence of harmonics can cause resonance conditions in power systems and dangerously high levels that can damage equipment and create safety risks. This can lead to voltage and current fluctuations. 25 To overcome these problems, for example, a Vienna Topology with three levels could be used. A rectifier is used. This design produces three different voltage levels: positive, zero and negative. The three-level structure significantly reduces voltage stress on individual components. By reducing these factors, it increases overall efficiency and minimizes harmonic distortion. This 30 These features make the Vienna rectifier particularly suitable for applications requiring high-quality DC power. This makes it advantageous. 6099 / TR 7 Traditional rectifiers face various challenges, including overheating and electromagnetic interference. This initiative is significant because it can lead to problems such as EMI and decreased efficiency in power systems. They generate harmonic currents. Reducing these harmonics is usually a comprehensive and costly process. This requires filtering. Furthermore, many conventional rectifiers have a low power factor. It suffers from inefficient power usage, which indicates that power distribution is inefficient. 5 This leads to an increase in reactive power in the system and higher operational losses. It opens. In addition, components such as diodes and switches in two-level rectifiers. High voltage stress on the components leads to higher failure rates and longer component lifespan. It contributes to its decrease. Vienna rectifiers produce lower harmonic currents and require less filtering. This results in obtaining a cleaner power supply due to the requirement for a higher power factor. Its correction capability allows it to align the input current with the voltage, thus It increases overall efficiency by reducing reactive power. Three-level topology components. This reduces voltage stress on the surface, increases reliability, and extends their service life by 15 This extends the lifespan. These factors result in lower switching losses and reduced harmonics. This contributes to achieving higher efficiency due to the degradation, and Vienna This makes the rectifier highly suitable for high-power applications. Despite these advantages, traditional 20s are still necessary to meet the evolving demands of many applications. The Vienna rectifier needs further improvements to accommodate varying load conditions. advanced technology that can dynamically adapt and optimize rectifier performance. A control algorithm is needed. Figure 1 illustrates the block diagram of the PWM technique applicable to the invention. The invention has a specific 25 According to the application, a DPWM technique for a Unidirectional Vienna Rectifier is as follows: It may include steps. Step 1, Injection Signal Calculation: Which three-phase SPWM modulation signal? Compared to others, its own phase switching element is either fully open or fully closed 30 If it is closer to driving that phase into the fully open or closed state, then... The injection signal is calculated. Thus, in 1 / 3 of the period of each phase. An injection signal is obtained that will not switch the switching element. This, used to obtain the injection signal used for standard DPWM 6099 / TR 8 It is one of the methods. However, this injection signal is sent to a unidirectional Vienna rectifier. This is not entirely feasible. Therefore, alternation control is provided in step 2. Step 2, Alternation Control: In this technique, before the injection signal is added, any It is checked whether the modulation signal alternation for the phase will change or not. 5 If the injection signal alternation would change, this injection signal is not added, and Standard SPWM continues to be used. The injection signal is applied to all three phases. If it does not change the alternation of the modulation signals, it is added to the signals. In DPWM, the term alternation refers to the 10¹² cycles of alternation applied over half-cycles of the PWM waveform. It refers to the switching strategy, where specific switches determine a part of the waveform. For some part of it, it remains in a fixed state, that is, either on or off. This is one of the characteristics of power switches. Switching by reducing the number of times it needs to change state during the AC cycle. It is implemented to reduce losses. In other words, alternation is a switching strategy. how it converts between phases or time intervals, switching losses at least 15 How to selectively disable certain switches to minimize and increase efficiency. It indicates that it holds. The DPWM strategy is inactive in different parts of the waveform. By changing the remaining phases, the output voltage and current can be controlled to an adequate level. It provides and allows for lower power losses. For example, In a three-phase system using DPWM, one phase may remain inactive during an alternation. (fully open or closed) and the other two phases can be switched. In the next alternation (one (in the next half-cycle), a different phase is kept inactive. Figures 2 and 3 show the three-phase T-type unidirectional NPC T-type Vienna Rectifier circuit and its general characteristics. It shows the control block diagram. 25 Figure 4 shows the block of a well-known DPWM technique developed for Bidirectional Vienna Rectifiers. It shows the diagram. In power electronics, Intermittent Pulse Width Modulation (DPWM) is used in switching. 30 reducing switching losses by turning off power transistors during part of the cycle It is a technique used for this purpose. This technique utilizes a dual system capable of managing current flow in both directions. It is particularly effective in directional systems. However, DPWM is similar to T-type unidirectional Vienna rectifiers. 6099 / TR 9 When applied to unidirectional systems, distortions such as those occurring in phase currents This can lead to problems. The main problem with using standard DPWM in a unidirectional Vienna rectifier is the current. The flow is allowed to occur in only one direction. In this topology, modulation is 5. the alternation of signals, i.e., the positive or negative half-cycle current alternation If they are incompatible, there will be no current flow. This mismatch is only one aspect of the Vienna rectifier. It is designed to rectify AC to DC in that direction and modulate signals current This occurs because if it is not aligned with the flow direction, the current can drop to zero. As a result, significant distortions occur in the phase currents, reducing harmonic performance to 10. This reduces the output and makes the standard DPWM technique unsuitable. Figure 5 shows a situation where the specified DPWM technique is used in a unidirectional Vienna Rectifier. It shows the phase current and the modulation signal. Indicated by red arrows in Figure 5. In some regions, the alternation of the modulation signal changes due to the DPWM technique. Depending on the connection, it can be observed that the current remains at 0 A. In this case, the harmonic performance of the current... will deteriorate significantly. Therefore, the traditional DPWM technique uses a one-way Vienna approach. It cannot be used for rectifiers. According to the invention, to solve the above problem, a 20 suitable for a one-way Vienna Rectifier is required. DPWM technique has been developed. Figure 6 shows a block diagram of a DPWM technique applicable to the invention. The DPWM technique suitable for the invention, for example, an injection signal to a sinusoidal PWM technique 25 It consists of adding. The idea behind the DPWM technique suitable for the invention is as follows: In summary: The injection signal generated for normal DPWM is converted into modulation signals. when added, it will change the alternation of the modulation signal of any phase. If it is large, the injection signal is not added at that moment, and sine PWM modulation continues. The alternation of the modulation signal of all phases, for example three phases, is the injection signal. If it does not change when added, an injection signal is added. Thus, the aforementioned phase currents The distortion occurring in the waveform can be prevented. In this way, the phase currents' waveforms can be corrected. This prevents any deterioration in its form. 6099 / TR Figure 7 shows the current waveform when the method consistent with the invention is applied. This shows that the deteriorations have been prevented. In summary, the DPWM technique applied in bidirectional systems lasts for 1 / 3 of a period. Since no switching is involved, the switching loss is reduced proportionally. When using standard DPWM technique in a Unidirectional Vienna Rectifier, the current waveform... Deformations occur in its form. The invention aims to prevent these deformations. A method has been developed. 10 According to one application of the invention, how long a period involves switching Whether required depends on the mains voltage and the desired output voltage. However, in all cases... This period is less than one-third of the total period. According to the invention, it is possible to reduce switching loss in a unidirectional Vienna Rectifier and a technique that can reduce the drain-source voltage peak level in switching elements It has been obtained. This application is not limited to the practices described herein. As defined in the claims 20 the scope of the invention in this form, other variations that are evident to experts in this field and It includes the changes.

Claims

6099 / TR 11 REQUESTS 1. It is a pulse width modulated rectifier, An alternating current (AC) rectifier is a device configured to rectify the input voltage. circuit; 5 direct current, DC, configured to control the output voltage. the switching circuit; and a pulse width modulation that switches the aforementioned switching circuit on and off, PWM includes a control unit configured to generate the signal. The control unit mentioned here will generate an injection signal, and this injection will be 10 It is configured to add the signal to the generated PWM signal.

2. The device is an intermittent pulse width modulation rectifier conforming to claim 1, and hereinafter referred to as such. The control unit, when the injection signal is added to the PWM signal, activates PWM. 15 to check whether the alternation of the signal changes or not It is being structured.

3. The rectifier is an intermittent pulse width modulation rectifier conforming to claim 2, where When the injection signal is added to the PWM signal, the alternation of the PWM signal increases. If it changes, the control unit in question also converts the injection signal to a PWM signal. It will not add anything and will only use the PWM signal to switch the switching circuit. It is configured to be used.

4. The rectifier is an intermittent pulse width modulation rectifier conforming to requirement 2 or 3, Here, the control unit also adds the injection signal to the PWM signal, resulting in PWM 25. If the alternation of the signal does not change, it will add the injection signal to the PWM signal. It is structured in this way.

5. The device is an intermittent pulse width modulation rectifier conforming to claim 1, and hereinafter referred to as such. The control unit, when the injection signal is added to multiple PWM signals, 30 If the alternation of the PWM signal for all phases remains unchanged, then for multiple phases... will generate excess PWM signals and add injection signals to the PWM signals It is structured in this way. 6099 / TR 12 6. This is an intermittent pulse width modulation rectifier conforming to claim 1, where In PWM signals, one of the phases, the first phase, is in phase with respect to the other phases. to drive the switching element fully open or fully closed If close, the injection signal's first phase is either fully open or fully closed. It is produced for use in driving. 5 7. This is an intermittent pulse width modulation rectifier conforming to claim 4, where The injection signal is one-third of the period of the aforementioned switching circuit. It is manufactured in such a way that it will not switch for a shorter period of time.

8. This is an intermittent pulse width modulation rectifier conforming to claim 1, where The switching off period depends on the AC input voltage and the DC output voltage.

9. A control method for a pulse width modulated rectifier: Rectifying alternating current (AC) input voltage using a rectifier circuit; 15 Control of direct current, DC, output voltage using a switching circuit to be done; and using a control unit to switch the circuit at a switching frequency generating a pulse width modulated (PWM) signal that switches it on and off It includes the following steps; 20 Here, an injection signal is generated and added to the produced PWM signal.

10. A pulse width modulated rectifier conforming to claim 1, conforming to claim 9. a computer containing instructions that enable the control method to execute its steps program. 25 11. The computer program that conforms to claim 10 is stored by the computer. a readable medium.

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