The Entrapment of Unfree Labor: Theory and Examples from India

In this article we explore some aspects of contemporary unfree labor in rural south India. We draw on 130 case studies and (informally) extensive field research. We do so in order to make the central point that the conditions of unfreedom are variable and subject to change but that the basic vulnerabilities are significant. Being unfree in a labor relationship is a contingent effect of a set of factors. We stress the role of (a) entrapment of laborers, (b) immiseration within bondage, and (c) barriers to exit from the labor contract. In explanations, structural factors are also important. The article forms a basis for further empirical research in a variety of global settings even beyond India

Towards an inclusive and safe Delhi : policy brief

Reduction of crime in general, and the safety of women and children in particular should remain a priority in social policy and governance. To reduce crimes against women in poor localities, sufficient access to water and a proper increase in the number of public toilets, while ensuring access round the clock will reduce risks of sexual violence. If the rates of crimes against women are calculated as a proportion of the urban female population, the crime rate witnessed an increase from 49.8 per 100,000 to 63.6 between 2011 and 2012. The rate of kidnappings and abductions of children is also highest in Delhi

Performance of a self-excited induction generator with DSTATCOM-DTC drive-based voltage and frequency controller

This paper presents the performance of a self-excited induction generator (SEIG) with a voltage and frequency controller (VFC) in a standalone microhydro power generating system. The VFC consists of a distribution static compensator (DSTATCOM) and a direct torque controlled variable frequency induction motor drive (VFIMD) operating as an electronic load controller (ELC). The DSTATCOM is an insulated-gate bipolar transistor-based three-leg voltage source inverter with a self-sustaining dc bus. The main objective of DSTATCOM is to regulate the system voltage through reactive power compensation. In addition to voltage regulation, the DSTATCOM compensates the harmonics generated by nonlinear loads as well as ELC. The ELC controls the system frequency through the active power balance. The VFIMD of the ELC drives a pump and it consumes the power in excess of consumer load power to maintain constant power generation at the SEIG terminals, which in turn regulates the system frequency. A prototype-proposed VFC is developed and tested with a variety of loads. Experimental results demonstrate that the proposed VFC can effectively control the system voltage and frequency

STATCOM-based controller for a three-phase SEIG feeding single-phase loads

This paper presents single-phase power generation using a three-phase self-excited induction generator (SEIG) working in conjunction with a three-phase static synchronous compensator (STATCOM). The STATCOM is employed to compensate the unbalanced currents caused by single-phase loads that are connected across the two terminals of the three-phase SEIG. Therefore, the SEIG is capable of feeding single-phase loads up to its rated power. Moreover, the STATCOM regulates the SEIG terminal voltage through reactive power compensation and also suppresses the harmonics injected by consumer loads. A single-phase synchronous D-Q frame theory-based control algorithm is used to generate gating pulses to the three-phase STATCOM. The proposed method of single-phase power generation from the three-phase SEIG is investigated experimentally on a 3.7-kW, 230-V, Y-connected induction machine. The performance of the SEIG-STATCOM system is evaluated for both linear and nonlinear single-phase loads. Furthermore, the performance of the SEIG at different terminal voltages is investigated and the terminal voltage corresponding to the maximum power output is identified

A microcontroller based speed controller for permanent magnet brushless DC motor

This paper presents a software controlled digital speed controller for Permanent Magnet Brushless DC motor. The scheme of the implemented drive system includes a position sensing mechanism, speed calculation from shaft encoder, speed controller, reference current generator, current controller, current controlled voltage source inverter and PMBL Motor. The hardware scheme developed consists of Hall effect current sensors used for the measurement of phase currents, optical isolation, driver circuit and MOSFET based Inverter. An assembly language program is written to realize PI speed controller, reference current generator, PWM current controller etc. The digitally controlled system provides high accuracy, reliability, flexibility and good system interaction and cost effective solution. The entire drive system is controlled by an intel 16b microcontroller. The drive system is simulated under real time conditions to investigate the performance of the drive under starting, reversal and load perturbation. The simulated results are compared with the experimental results. Experimental results obtained from a prototype drive are shown to confirm the validity of the simulated results

Static synchronous compensator-variable frequency drive for voltage and frequency control of small-hydro driven self-excited induction generators system

In this study, a static synchronous compensator (STATCOM) along with a variable frequency drive (VFD), is proposed for voltage and frequency control of a small-hydro turbine driven self-excited induction generator (SEIG) system. STATCOM is used to control SEIG terminal voltage through variable reactive power injection. A control algorithm based on adaptive noise cancellation filter is proposed for STATCOM control. A field oriented controlled VFD feeding an induction motor is used to control system frequency. The VFD consumes active power in excess of consumer loads and thereby it regulates the system frequency. The excess power consumed by the VFD is utilised for pumping water to either an overhead storage tank or irrigation purposes. Besides the voltage control as primary objective, the STATCOM also provides harmonic currents compensation and load balancing under unbalanced non-linear loads. The proposed method of voltage and frequency control using STATCOM-VFD combination is implemented on a 3.7 kW SEIG and the test results are presented to demonstrate its performance

Design and implementation of dynamic electronic load controller for three-phase self-excited induction generator in remote small-hydro power generation

This study presents design and implementation of a dynamic electronic load controller (DELC) for voltage and frequency control of a three-phase self-excited induction generator (SEIG) driven by constant power unregulated small-hydro turbine. This DELC is a combination of insulated-gate bipolar transistor-based voltage sourced converter (VSC) and variable frequency drive (VFD) which is connected across the DC link of VSC. The VFD operates in direct torque control mode and is coupled with a pumping system. The DELC is connected at point of common coupling in parallel with consumer loads. The VSC provides instantaneous control of the SEIG voltage through reactive power compensation. The VFD consumes the power in excess of consumer loads to maintain constant generator output power which in turn regulates the frequency. The excess generated power consumed by the VFD is used to pump water either to an overhead tank or for irrigation purposes. The performance of the proposed DELC of SEIG is demonstrated under various types of loads such as linear/non-linear, balanced/unbalanced loads and so on. Test results recorded on a developed DELC of SEIG exhibit simultaneous voltage and frequency control capabilities of the DELC under varying loads