Analysis of common-mode voltage elimination of PWM inverter with auxiliary inverter
7
Citation
4
Reference
20
Related Paper
Citation Trend
Abstract:
This paper discusses analysis of common-mode voltage elimination of a PWM inverter with an auxiliary inverter. The main inverter and the small capacity auxiliary inverter are connected at the neutral point of the LC filter. The auxiliary inverter compensates common-mode voltages of the main inverter. Additionally, because the auxiliary inverter does not output active power, the capacity of the inverter is small. Common-mode voltages results from rapid change of output voltage when the switching is done in inverter. The common-mode currents flow through parasitic capacitances. Theoretically, the auxiliary inverter is able to perfectly compensate the common-mode voltage generated by the main inverter. This paper discusses the analysis of the common-mode voltage elimination of the inverter.Keywords:
Common-mode signal
Grid-tie inverter
Cite
A new multilevel PWM inverter using a half-bridge and full-bridge cells is proposed for the use of stand-alone photovoltaic inverters. The configuration of the proposed multilevel PWM inverter is based on a prior 11-level shaped PWM inverter. Among three full-bridge cells employed in the prior inverter, one cell is substituted by a half-bridge cell. Owing to this simple alteration, the proposed inverter has three promising merits. First it increases the number of output voltage levels resulted in high quality output voltages. Second, it reduces two power switching devices by means of employing a half-bridge cell. Third, it reduces power imposed on a transformer connected with the half-bridge unit. That is to say, most power is transferred to loads via cascaded transformers connected with low switching inverters, which are used to synthesize the fundamental output voltage levels whereas the output of a transformer linked to a high switching inverter is used to improve the final output voltage waves; thus, it is desirable in the point of the improvement of the system efficiency. By comparing to the prior 11-level PWM inverter, it assesses the performance of the proposed inverter as a stand-alone photovoltaic inverter. The validity of the proposed inverter is verified by computer-aided simulations and experimental results.
Grid-tie inverter
Cite
Citations (0)
Conventional Pulse Width Modulated (PWM) inverters create common mode voltage with high frequency and dv/dt. Common-mode voltage causes motor shaft voltage, bearing current and electromagnetic interference (EMI) in the induction motor drive system. In this paper, a common-mode voltage eliminated 2-level space vector pulse width modulation scheme based on a cascaded 3-level inverter is presented. When the inverter is controlled by PWM, the common-mode voltage dropped between the neutral point of the motor and the negative terminal of the inverter supply is of alternating nature. In the proposed scheme, inverter voltage vectors having the same common mode voltage are used to generate the PWM signal. This eliminates alternating common-mode voltage and its adverse effects. The scheme is experimentally verified using a 3-level inverter realized by connecting two 2-level inverters in cascade configuration and experimental results are presented to validate the scheme.
Common-mode signal
Cite
Citations (3)
Control of a three-phase inverter with neutral-line voltage injection is proposed to improve the output voltage waveform. This inverter consists of a main three-phase inverter and an auxiliary single-phase inverter; the main inverter acts in the 120-degree conduction mode and the auxiliary inverter behaves as a wave shaper with three times frequency of the main frequency. The main inverter converts almost all the input dc power to ac power in discontinuous rectangular waveform. The auxiliary inverter is applied to lower the output voltage total-harmonic-distortion (THD). Design of the proposed inverter is presented in the paper. Performance of the total inverter is investigated in theory and experiment. The output three-phase voltages had a THD of about 4.5% in experiment. The practicability of the control method is confirmed.
Grid-tie inverter
Three-phase
Cite
Citations (0)
Conventional pulse width modulation (PWM) schemes for dual inverter fed drive synthesise the reference voltage as a switched average of minimum three voltage vectors from individual inverters. As a result, the number of transitions in the inverter increases. This paper introduces a family of PWM methods, where the reference voltage is synthesised as a switched average of only two voltage vectors from individual inverter. This leads to simultaneous clamping of two phases, thus reducing the number of switching transitions in the inverter. The concept and realisation of the proposed PWM are discussed and compared with conventional bus clamping PWM methods on the basis of inverter power loss and common mode voltage generation. The proposed PWM is experimentally validated on an open end winding induction motor drive operating with open loop control. Synchronised carrier modulation is considered for PWM generation.
Clamper
Modulation (music)
Cite
Citations (2)
This paper presents a dual-bridge inverter approach to eliminate the motor common-mode voltage. This inverter which consists of two inverters to be connected in parallel does not generate the common-mode voltage, and can drive standard three-phase three-wire induction motors. Additionally, because one inverter does not output active power, the capacity of the inverter is very small. The effectiveness of the proposed method is verified experimentally.
Common-mode signal
Grid-tie inverter
Mode (computer interface)
Cite
Citations (7)
This paper presents a characteristic comparison between a five-leg inverter and a nine-switch inverter. The five-leg inverter and the nine-switch inverter is a single inverter that can drive two AC motors independently. Concretely, we show a circuit architecture of both inverters, a modulation method for an independent drives and a division of voltage utility factor. Moreover, investigate about the inverter losses and a switching device capacity in driving two AC motors independently and adapting a control method to decrease the inverter losses.
Grid-tie inverter
Modulation (music)
Cite
Citations (52)
In a PWM inverter, the PWM signal with the dead-time is usually used to protect the short-phenomenon of a pair of main switching devices in the inverter. The dead-time causes the waveform distortion in the output voltage and interrupts the high carrier frequency drive of the inverter. In order to solve these problems, a novel PWM inverter is proposed in this paper. The proposed PWM inverter is realized by performing zero current switching at the turn-on of the main switching devices and generates the output voltage without a waveform distortion, although the inverter is driven by the PWM signal with the dead-time. The zero current switching is achieved by connecting in series an inductor and a capacitor between the output terminals of a conventional inverter.
Sine wave
SIGNAL (programming language)
Dead time
Grid-tie inverter
Distortion (music)
Cite
Citations (9)
This paper discusses improvement of common-mode voltage elimination ability of a PWM inverter with an auxiliary inverter. The main inverter and the small capacity auxiliary inverter are connected at the neutral point of the LC filter. The auxiliary inverter compensates common-mode voltages of the main inverter. Additionally, because the auxiliary inverter does not output active power, the capacity of the inverter is small. Common-mode voltages results from rapid change of output voltage when the switching is done in inverter. The common-mode currents flow through parasitic capacitances. Theoretically, the auxiliary inverter is able to perfectly compensate the common-mode voltage generated by the main inverter. Actually, however, the common-mode voltage appeared by the dead-time effect. This paper presents the influence of the dead time to the common-mode voltage of the PWM inverter with the auxiliary inverter and its compensation.
Common-mode signal
Grid-tie inverter
Cite
Citations (16)
Commutation
Chopper
Grid-tie inverter
Rectifier (neural networks)
Cite
Citations (0)
This paper aimed at reactive power compensation of three-phase balancing loads for 6kV medium-voltage source, and proposed a new type of main-auxiliary structure STATCOM (static synchronous compensator) that can be directly connected to power source. This structure combined the characteristics of both diode-clamped multilevel inverter and cascaded multilevel inverter: the main inverter took the form of three-level diode-clamped inverter, while the auxiliary inverter adopted H bridge (full bridge) inverter. The three auxiliary H-bridge inverters were connected to the corresponding phase of main inverter in series, so that both of them constituted a five-level hybrid inverter. In this paper, the auxiliary H-bridge inverter was designed to produce a square wave voltage whose frequency equaled that of AC power supply, and the square wave acted as basic part of expected output phase voltage. Main inverter had two functions: one was to generate the compensatory part of expected output phase voltage; the other was to compensate harmonic component of output voltage. In the end, the superiority of the proposed STATCOM structure was validated by simulation.
Grid-tie inverter
Three-phase
Harmonic
Cite
Citations (0)