Mikko Kuisma

Lappeenranta – Lahti University of Technology LUT · Department of Energy

Maailma ympärillämme muuttuu jatkuvasti ja koulutuksen on vastattava muuttuviin tarpeisiin. Pelkällä yksittäisen alan substanssitiedolla ei enää pärjää työelämässä. Nykyisin tarvitaan monipuolisia tietoja, taitoja, asenteita ja verkostoja. Projektimaisesti toteutetuilla kursseilla pyritään aktivoimaan erilaiset oppijat ja kehittämään teknisten tiet...

Modeling the photoelectric response of dry bacteriorhodopsin (bR) sensors has commonly been carried out by following the theory of linear time-invariant systems. However, it has been reported that the time constants of the photovoltage responses of such sensors vary depending on whether the sensor is measured when the incident light is switched on...

Traditionally, condition monitoring of power semiconductor modules has been based on electrical measurements. Acoustic emission has been utilized for condition monitoring in many other applications, but is an unknown phenomenon in power semiconductor modules. In this paper the authors present an experimental setup used to show that acoustic emissio...

Common mode (CM) electromagnetic interference in power lines are typically reduced with a CM filter, which consists of discrete capacitors and inductors. An air-cored EMI filter with CM choke and integrated X and Y capacitors utilizing the parasitic capacitance of the windings is proposed. Its benefits include better high frequency performance, red...

Spreading the signal spectrum is a widely used technique in telecommunication applications. Variable-frequency and spread spectrum modulation methods can also be utilized in power electronic applications to improve electro-magnetic compatibility (EMC). This paper gives an overview to variable-frequency techniques in power electronics with experimen...

In this paper, the novel concept of using heat flux sensors (HFS) to measure arterial pulse on the skin surface is validated. The heat flux (HF) signal is compared with simultaneously measured electrocardiogram (ECG) and photoplethysmography (PPG) signals during both rest and initial recovery from exercise. It is found that the waveform measured wi...

In this paper, the novel concept of using heat flux sensors (HFS) to measure arterial pulse on the skin surface is validated. The heat flux (HF) signal is compared with simultaneously measured electrocardiogram (ECG) and photoplethysmography (PPG) signals during both rest and initial recovery from exercise. It is found that the waveform measured wi...

Different wearable biosignal measurement applications require minimally obtrusive and highly sensitive sensors and methods of transducing the heart pulse into an electric signal. At the same time, the sensors should have minimal power consumption and preferably provide information about more than just the heart rate. In this study, a method employi...

Wearable electronics are often used for estimating the energy expenditure of the user based on heart rate measurement. While heart rate is a good predictor of calorie consumption at high intensities, it is less precise at low intensity levels, which translates into inaccurate results when estimating daily net energy expenditure. In this study, hear...

Heat flux sensors have potential in enabling applications that require direct and instantaneous tracking of thermal energy transfer. To facilitate widespread use of the sensors, the sensors have to be robust and feasible to implement, while maintaining high sensitivity, fast response time, and low thermal obtrusiveness. However, most currently avai...

Heat flux sensors have potential in enabling applications that require tracking of direct and instantaneous thermal energy transfer. To facilitate their use, the sensors have to be robust and feasible to implement, while maintaining high sensitivity and a fast response time. However, most commercially available heat flux sensors are expensive to ma...

Wearable electronics are often used for estimating the energy expenditure of the user based on heart rate measurement. While heart rate is a good predictor of calorie consumption at high intensities, it is less precise at low intensity levels, which translates into inaccurate results when estimating daily net energy expenditure. In this study, hear...

Heat flux sensors have potential in enabling applications that require tracking of direct and instantaneous thermal energy transfer. To facilitate their use, the sensors have to be robust and feasible to implement, while maintaining high sensitivity and a fast response time. However, most commercially available heat flux sensors are expensive to ma...

Wearable electronics are often used for estimating the energy expenditure of the user based on heart rate measurement. While heart rate is a good predictor of calorie consumption at high intensities, it is less precise at low intensity levels, which translates into inaccurate results when estimating daily net energy expenditure. In this study, hear...

The application of the gradient heat flux sensor as a failure and aging indicator of the power electronics was studied in this paper. Conducted experiments shown that the heat flux sensor attached to the insulated-gate bipolar transistor’s (IGBT’s) base plate can provide realtime heat flux monitoring. Condition monitoring (CM) model implemented in...

This paper proposes and investigates the application of the gradient heat flux sensor (GHFS) for measuring the local heat flux in power electronics. Thanks to its thinness, the sensor can be placed between the semiconductor module and the heat sink. The GHFS has high sensitivity and yields direct measurements without an interruption to the normal p...

Poster describes how the use of drones enhances the possibility of gathering Situational Awareness with higher tempo.

Recently, there have been experiments where the acoustic emission sensors have been used in the investigation of power semiconductor components. In this paper the authors present their observations of measurement related challenges they have encountered while doing such experiments. Special focus is on sensor related difficulties. The main result o...

Bacteriorhodopsin is considered an important biomolecule for biochemical and technology-oriented studies. The modeling and functionality of bacteriorhodopsin sensors have been extensively studied, but the studies lack the analysis of the errors present in the measurements. Further, the impacts of these errors on photoelectric measurements are mostl...

The photoelectric response of dry bacteriorhodopsin sensors varies depending on whether the incident light is on or off. To model this behavior, we have proposed an electrical equivalent circuit that has a capacitor that varies with the light intensity. In this paper, the proposed model is experimentally validated and found to be appropriate even w...

The authors show for the first time that acoustic events are related to the failure of transistors. An experimental setup is presented, that was used to make a sample of 26 insulated gate bipolar transistors (IGBT) to fail. The acoustic events in the transistors were monitored. It was discovered that two distinct types of acoustic events are relate...

A recent paper showed that the switching operation of a power semiconductor module causes an acoustic emission to take place. In this study, that experiment is repeated using a different kind of acoustic emission sensor. The same conclusion is reached in this stydy as in the previous paper: an acoustic emission takes place as a result of the switch...

Electric vehicle competitions have been organized in order to test the limits of technology. In this paper, we describe a competition for students and the public. The competition was held in Lappeenranta in 2013. We also analyze what kinds of vehicles were used and what the winning strategy was.

Purpose – The purpose of this paper is to present observations of a EUR-ACE accreditation process in a Finnish university. The study demonstrates the effects (benefits, effort and resources required) of accreditation as seen by the university management and teaching staff. Design/methodology/approach – The material of the study was gathered by con...

Aiemmin opetuksessa on korostettu tiedon ja muistamisen tärkeyttä. Nyt tiedon muistaminen on menettänyt merkitystä, sillä lähes kaikki tieto on saatavilla lähimmän tietokoneen tai älylaitteen avulla. Tärkeimmiksi taidoksi on muodostumassa tutkivan oppimisen ja tiedon luomisen taidot. Yliopistojen on vastattava tähän haasteeseen, jota jo alakoulussa...

Photoactive biomolecules have been proposed for several technical applications including optoelectronics. Wild-type bacteriorhodopsin is used as an example molecule to study the photoelectric measurements of dry sensor films and problems related to the implementation and interpretation of the measurement results. Thick bacteriorhodopsin films have...

In this paper, the design and implementation of an energy measurement system for an electric vehicle competition is described. The system consists of PC-based software and a processor-controlled stand-alone measuring unit with an analog front-end, an SD memory card, a radio link, and a USB interface. The work was carried out as a part of a universi...

Lappeenrannan teknillinen yliopisto (LUT) päätti toteuttaa ulkopuolisen arvioinnin parantaakseen koulutuksensa laatua. Arviointimenetelmäksi valittiin kansainvälinen akkreditointi, ja tekniikan alaa arvioitiin ASIIN- ja EUR-ACEkriteeristöjen mukaan. Lappeenrannan teknillisen yliopiston laadunarviointi oli ensimmäinen teknillistieteellisen alan akkr...

This paper continues the design considerations of a novel type of passive filter called hybrid LC filter (HLCF). The filter is aimed at significant reduction in high-frequency differential mode (DM) and common mode (CM) currents in speed-controlled ac drives. A model of the HLCF is presented. Based on the model, a transfer function of the HLCF is f...

http://urn.fi/URN:ISBN:978-952-265-255-3

Transferable skills are vital in modern engineering work. Educational institutions are forced to reassess their education; along with theoretical content, transferable competences are emphasized. This paper demonstrates how teaching transferable skills, such as team work, oral and writing skills, project, time, and financial management, are integra...

This paper introduces an alternative implementation of the traditional LC filter, called hybrid LC filter (HLCF). The construction described in this paper contains two foil windings that integrate inductance and capacitance into one unit. The main aspects of the HLCF design are considered. The experimental data show that the device proposed here ca...

A filter appliance comprises first electrical terminals (201-203) for connecting to a multiphase electrical converter device, second electrical terminals (204-206) for connecting to a load, main current coils formed of foil conductors and connected between the first and the second electrical terminals, and shielding coils whose first ends are elect...

The fuel cell has special electrical characteristics which set challenging requirements for power conditioning units. Many of these requirements origin from the operation principle and physical structure of the fuel cell and cannot be ignored in the design of power electronics. In this paper the operational requirements for power conditioning units...

Electromagnetic interference (EMI) remains one of the main problems in switch mode power supplies (SMPS). Various EMI reduction schemes for switching converters using switching modulation have been proposed over the last decades. These variable-frequency (VF) modulation techniques include quasi-random system clock generation, random or quasi-random...

The group size of students tend to be quite high on basic courses. To ensure good learning results students must be guided to do as much as possible by themselves. With limited teaching resources this might cause problems. One implementation of problem based learning (PBL) in teaching electronics is presented in this paper. The target of the implem...

Active Noise Control (ANC) has been used in applications where the noise is periodic. Usually random or impulsive noise cancellation is neglected in these conventional applications. Development of signal processing, new modeling tools and electro-acoustic components has made ANC for impulsive noise possible. ANC for firearm-generated noise has been...

Requirements and analysis of various system components and transducers for active impulse noise control (AINC) are studied in this paper. AINC sets different requirements for system hardware than conventional active noise control (ANC). If the noise is periodic, amplitude and phase response of the ANC system is usually analyzed. According to litera...

Electromagnetic interference (EMI) is usually difficult to predict and the interference problems may dramatically lengthen the time-to-market of a new power supply product. The possibility of predicting the EMI-spectrum from the switching function of a switching power supply by means of simulation is analyzed in this paper. Simulated spectra are co...

Spread-spectrum techniques have raised their importance as a common EMI-reduction technique in power supplies. Ability to track and measure such a signal is vital. Analysis and synthesis of an effective spread-spectrum sequence is also important. Pulse-type and apparently random interference are other types of signals which are hard to detect and m...

Numerous variable-frequency (VF) EMI-reduction schemes have been proposed over the last decades. The aim of these VF or spread-spectrum techniques is to reduce both the measurable and effective undesirable electromagnetic noise of a switch mode power supply. Conducted RF-interference measurements have been reported in literature. However, low frequ...

Switching power supplies are usually implemented with a control circuitry that uses constant clock frequency turning the power semiconductor switches on and off. A drawback of this customary operating principle is that the switching frequency and harmonic frequencies are present in both the conducted and radiated EMI spectrum of the power converter...

The focus of this paper is on the implementation of sliding mode control (SMC) for switch mode power supply. A brief analysis of the control structure is explained followed by a block diagram showing the internal structure of the control loops and the way they are connected to the converter. The buck converter was chosen as an example and the simul...

Switch mode power supplies have been controlled using different control algorithms like PID control, current mode programmed control etc. Many control tools were used to implement these control techniques e.g. analog operational amplifier, microprocessor. This paper focuses on using a new control tool called dSPACE^™ for controlling the s...

Traditional pulse width modulated (PWM) power converter operates on a constant switching frequency. This frequency is also presented in the electromagnetic interference (EMI) -spectrum of the converter. During the last decade, intensive study of EMI-reduction techniques, including spread spectrum technology, in the field of power electronics has be...

The theory of sliding mode control (SMC) to switch mode power supplies have been widely investigated in literature, but most of the papers have focused on the theoretical aspects of this control without any practical implementations. This paper links the theory to practical power supply design. Analysis and experimental study of buck converter is p...

Spreading the signal spectrum is a widely used technique in telecommunication applications. The technique is used to hide the sent signal from potential extraneous receivers or to minimise the use of the limited radio recourse. In power electronics spread spectrum techniques are also in use. There the interest on these techniques is partially based...

Switch mode power supplies (SMPS) that have a periodic switching pattern have an EMI spectrum that contains switching frequency and its harmonic frequencies with significant amplitude at least up to 21 st harmonic. Two methods to reduce the harmonic frequencies basing on the spread spectrum technology are presented in this paper. First method is ba...

Several solutions suitable for measuring high currents that are typical in power electronic devices such as motor inverters, welding power supplies, induction heating devices etc. are presented. The accuracy and suitable applications of each current measuring system are discussed. Modern current measurement systems based on magnetic field sensing d...