Mohannad Jabbar Mnati

A Smart Voltage and Current Monitoring System for Three Phase Inverters Using an Android Smartphone Application

In this paper, a new smart voltage and current monitoring system (SVCMS) technique is proposed. It monitors a three phase electrical system using an Arduino platform as a microcontroller to read the voltage and current from sensors and then wirelessly send the measured data to monitor the results using a new Android application. The integrated SVCMS design uses an Arduino Nano V3.0 as the microcontroller to measure the results from three voltage and three current sensors and then send this data, after calculation, to the Android smartphone device of an end user using Bluetooth HC-05. The Arduino Nano V3.0 controller and Bluetooth HC-05 are a cheap microcontroller and wireless device, respectively. The new Android smartphone application that monitors the voltage and current measurements uses the open source MIT App Inventor 2 software. It allows for monitoring some elementary fundamental voltage power quality properties. An effort has been made to investigate what is possible using available off-the-shelf components and open source software.

A New Synchronization Technique of a Three-Phase Grid Tied Inverter for Photovoltaic Applications

Three-phase grid synchronization is one of the main techniques of the three-phase grid connected power inverters used in photovoltaic systems. This technique was used to reach the fast and accurate three-phase grid tied inverter synchronization. In this paper a new synchronization method is presented on the basis of integrating the grid voltage two times (line-to-line or phase voltage). This method can be called “double integral synchronization method” (DISM) as it integrates the grid voltage signals two times to generate the reference signals of three-phase photovoltaic inverter currents. DISM is designed and simulated in this paper to operate in both analog and digital circuits of three-phase photovoltaic inverter system with the same topology. The digital circuit design and dsPIC33FJ256GP710A as a microcontroller (the dsPIC33FJ256GP710A with the Explorer 16 Development Board from microchip) was used practically in this paper to generate and control the sine pulse width modulation (SPWM) technique according to DISM for three-phase photovoltaic inverter system. The main advantage for this method (DISM) is learning how to eliminate the integration constant to generate the reference signals without needing any reference signals or truth table, just the line-to-line or phase voltage of grid.

New Pulse Width Modulation Technique to Reduce Losses for Three-Phase Photovoltaic Inverters

Nowadays, most three-phase, “off the shelf” inverters use electrolytic capacitors at the DC bus to provide short term energy storage. However, this has a direct impact on inverter lifetime and the total cost of the photovoltaic system. This article proposes a novel control strategy called a 120° bus clamped PWM (120BCM). The 120BCM modulates the DC bus and uses a smaller DC bus capacitor value, which is typical for film capacitors. Hence, the inverter lifetime can be increased up to the operational lifetime of the photovoltaic panels. Thus, the total cost of ownership of the PV system will decrease significantly. Furthermore, the proposed 120BCM control strategy modulates only one phase current at a time by using only one leg to perform the modulation. As a result, switching losses are significantly reduced. The full system setup is designed and presented in this paper with some practical results.

Frequency synchronization of a single-phase grid-connected DC/AC inverter using a double integration method

ABSTRACT Many traditional grids have started to integrate the DC/AC inverters in their networks. This requires a good control to enhance the power quality. The grid frequency behaviour is one of the principal indicators that reveal the power quality. Therefore, it must be strongly controlled. Up to now, the most popular frequency synchronization method is based on phase-locked loop (PLL) control. It is known that setting a current proportional to voltage does not work well and it creates a negative resistor in a wide frequency range because the circuit is not passive. This paper presents an alternative idea of synchronization of a single-phase grid-connected DC/AC inverter by using a double integration method. It is simpler than PLL since it needs neither a phase comparator, nor a local oscillator. It provides a signal in phase with the current. The art of the method is how to remove the integrating constants without degrading the signal.

Design of a half-bridge bootstrap circuit for grid inverter application controled by PIC24FJ128GA010

This paper explains a design of a bootstrap circuit to drive a half-bridge inverter circuit, The standard bootstrap circuit consists of a driver IC and three external components (RBoot, DBoot and CBoot) for inverter application. However, the bootstrap circuits had shown some weakness such as having adequate components to allow a high performance. This article shows how to select the bootstrap driver circuit parameters and using IR2112 to drive a power IGBTs inverter with a low energy consumption. In this paper, the PWM signal is generated by using a PIC24FJ128GA010 microcontroller and interfaced to the bootstrap circuit. The paper discusses the advantage and disadvantages of the bootstrap.