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Accurate control of both the timing and quantity of injection events is critical for engine performance and emissions. The most serious problem which reduces the accuracy of the control operation in such systems is a time delay of the responsiveness for the opening and closing operation of the electromagnetic valve. Modern electronic control systems should be capable of driving high speed solenoid injectors at a very fast switch frequency with high efficiency and acceptable power requirements. In this paper, the dynamic characteristic of a high speed servo-hydraulic solenoid injector for diesel engine, with different driving circuits and control methods, is investigated. A pre-energizing control strategy based on a dual power supply is applied to speed up the opening response time of the injectors.

With the increasing worldwide concern on environmental pollution, battery electrical vehicles (BEV) have attracted a lot attention. However, it still couldn’t satisfy the market requirements because of the low battery power density, high cost and long charging time. The range-extended electrical vehicle (REEV) got more attention because it could avoid the mileage anxiety of the BEVs with lower cost and potentially higher efficiency. When internal combustion engine (ICE) works as the power source of range extender (RE) for REEV, its NVH, emissions in starting process need to be optimized. In this paper, a 2-cylinder PFI gasoline engine and a permanent magnet synchronous motor (PMSM) are coaxially connected. Meanwhile, batteries and load systems were equipped. The RE co-control system was developed based on Compact RIO (Compact Reconfigurable IO), Labview and motor control unit (MCU).

For internal combustion engine systems, lean and diluted combustion is an important technology applied for fuel efficiency improvement. Because of the thermodynamic boundary conditions and the presence of in-cylinder flow, the development of a well-sustained flame kernel for lean combustion is a challenging task. Reliable spark discharge with the addition of enhanced delivered energy is thus needed at certain time durations to achieve successful combustion initiation of the lean air-fuel mixture. For a conventional transistor coil ignition system, only limited amount of energy is stored in the ignition coil. Therefore, both the energy of the spark discharge and the duration of the spark discharge are bounded. To break through the energy limit of the conventional transistor coil ignition system, in this work, an adaptive spark ignition system is introduced. The system has the ability to reconstruct the conductive ion channels whenever it is interrupted during the spark discharge.

According to the requirements of two-wheel vehicle's future market and the characteristic of urban road conditions in China, the advantages and disadvantages of three basic configurations for the Hybrid Electric Vehicle are compared, finally, the serial hybrid configuration is chosen to be applied to hybrid Electric Moped solution. The selection principle of main components of this hybrid powertrain system includes ICE, generator, battery and hub motor, and the optimal match for performance parameters of these components are introduced in this paper. Then, a hybrid system model is established based on AVL-CRUISE. The simulations of fuel efficiency and exhaust emissions for both serial hybrid moped and conventional motorcycle is offered.

In this paper, based on the plug-in series hybrid electric vehicle development project, the vehicle technology solutions and the match of power system parameters were analyzed. The vehicle control strategies were identified and optimized according to plug-in hybrid vehicle features. The plug-in series hybrid, rule-based logic threshold switching control strategy, charge depleting (CD) mode and charge-sustaining (CS) mode are chosen according to the key factors, such as the environment, performance requirements, technical requirements and cost. And then the structure and model of vehicle control strategy were established to carry out vehicle energy management and power system control. The parameter selection, electric drive system matching, energy storage system design based on the requirement of vehicle performance, system architecture and control strategy are presented.

Future clean combustion engines tend to increase the cylinder charge to achieve better fuel economy and lower exhaust emissions. The increase of the cylinder charge is often associated with either excessive air admission or exhaust gas recirculation, which leads to unfavorable ignition conditions at the ignition point. Advanced ignition methods and systems have progressed rapidly in recent years in order to suffice the current and future engine development, and a simple increase of energy of the inductive ignition system does not often provide the desired results from a cost-benefit point of view. Proper design of the ignition system circuit is required to achieve certain spark performances.

In order to investigate the impacts of recirculated exhaust gas temperature on gasoline engine combustion and emissions, an experimental study has been conducted on a turbocharged PFI gasoline engine. The engine was equipped with a high pressure cooled EGR system, in which different EGR temperatures were realized by using different EGR coolants. The engine ran at 2000 r/min and 3000 r/min, and the BMEP varied from 0.2MPa to 1.0MPa with the step of 0.2MPa. At each case, there were three conditions: 0% EGR, 10% LT-EGR, 10% HT-EGR. The results indicated that LT-EGR had a longer combustion duration compared with HT-EGR. When BMEP was 1.0 MPa, CA50 of HT-EGR advanced about 5oCA. However, CA50 of LT-EGR could still keep steady and in appropriate range, which guaranteed good combustion efficiency. Besides, LT-EGR had lower exhaust gas temperature, which could help to suppress knock. And its lower exhaust gas temperature could reduce heat loss. These contributed to fuel consumption reduction.

This research was concerned with the use of Exhaust Gas Recirculation (EGR) improving the fuel economy over a wide operating range in a downsized boosted gasoline engine. The experiments were performed in a 1.3-Litre turbocharged PFI gasoline engine, equipped with a Low Pressure (LP) water-cooled EGR system. The operating conditions varied from 1500rpm to 4000rpm and BMEP from 2bar to 17bar. Meanwhile, the engine’s typical operating points in NEDC cycle were tested separately. The compression ratio was also changed from 9.5 to 10.5 to pursue a higher thermal efficiency. A pre-compressor throttle was used in the experiment working together with the EGR loop to keep enough EGR rate over a large area of the engine speed and load map. The results indicated that, combined with a higher compression ratio, the LP-EGR could help to reduce the BSFC by 9∼12% at high-load region and 3∼5% at low-load region.

Research studies have suggested that changes to the ignition system are required to generate a more robust flame kernel in order to secure the ignition process for the future advanced high efficiency spark-ignition (SI) engines. In a typical inductive ignition system, the spark discharge is initiated by a transient high-power electrical breakdown and sustained by a relatively low-power glow process. The electrical breakdown is characterized as a capacitive discharge process with a small quantity of energy coming mainly from the gap parasitic capacitor. Enhancement of the breakdown is a potential avenue effectively for extending the lean limit of SI engine. In this work, the effect of high-power capacitive spark discharge on the early flame kernel growth of premixed methane-air mixtures is investigated through electrical probing and optical diagnosis.

To improve the cold start performance and to reduce the misfire occurrence at cold start, the start-up strategy of total stoichiometric ratio combined with local rich mixture was applied in the study. The effect of injection strategy (the 1st injection timing, 2nd injection timing, 1st and 2nd fuel injection proportion and ignition timing) on the cold start HC emissions in the initial 10 cycles were investigated in a Two stage direct injection (TSDI) gasoline engine. The transient HC and NO emissions in the initial 10 cycles were analyzed, when the fuels are injected in the only 1st cycle and in the followed all cycles. The transient misfiring HC emissions were compared between the single and two-stage injection modes. In addition, the unburned HC (UBHC) emissions in the 1st cycle are compared among the TSDI engine, Gasoline direct injection (GDI) engine, Port fuel injection (PFI) engine and Liquefied petroleum gaseous (LPG) engine at the stoichiometric ratio.

Reducing the pumping loss, and thus, the fuel consumption of gasoline engine at part load, a two-stage intake valve lift system was implanted into a PFI engine. A corresponding engine model was set up with GT-power as well, which can simulate the effect of two-stage intake valve lift and different EGR rates on fuel economy performance and on combustion condition of a gasoline engine. Based on simulation results, the valve lift control strategy and EGR control strategy was studied in this paper. Results showed that at low engine speed, when SMALL LIFT was used, the tumble flow and the combustion process in cylinder was improved and burn time duration became shorter, resulting in higher indicated efficiency and lower fuel consumption than by LARGE LIFT. With the introduction of the exhaust gas recirculation (EGR), lower fuel consumption was acquired.

With the increasing concern on environmental pollution and CO2 emission all over the world, range-extended electrical vehicle (REEV) has gradually got more attention because it could avoid the mileage anxiety of the battery electrical vehicles (BEV) and get high energy efficiency. Nevertheless, NVH performance of internal combustion engine range extender (ICRE) is a critical problem that affects the driving experiences for REEV. In this paper, a two-cylinder PFI gasoline engine and a permanent magnet synchronous motor (PMSM) are coaxially mounted to run as an ICRE. The ICRE control system was established based on Compact RIO hardware and LabVIEW, who has the functions of the intake throttle PID closed-loop control, autonomous ICRE operation control, and speed PID closed-loop control. In this paper, the gasoline engine was first driven to the idle condition by PMSM in speed-control mode.

The characteristics of three-way-catalyst during engine start process were investigated based on a simulated start/stop test system for HEV application. Although the catalyst has already reached its light-off temperature, the conversion efficiency is poor during engine start process due to the deviation of lambda from stoichiometric. The high concentration hydrocarbon emission spike can be stored by catalyst substrate temporarily, then it is released. This dynamic process decreases the conversion efficiency for the following exhaust hydrocarbon emission. When the initial temperature of catalyst substrate before engine start increased from 150°C to 400°C, the conversion efficiency for both the hydrocarbon and NO are increased.

In this paper an estimation method on location of peak pressure (LPP) employing flame ionization measurement, with the spark plug as a sensor, was discussed to achieve combustion parameters estimation at quick start of HEV engines. Through the cycle-based ion signal analysis, the location of peak pressure can be extracted in individual cylinder for the optimization of engine quick start control of HEV engine. A series of quick start processes with different cranking speed and engine coolant temperature are tested for establishing the relationship between the ion signals and the combustion parameters. An Artificial Neural Network (ANN) algorithm is used in this study for estimating these two combustion parameters. The experiment results show that the location of peak pressure can be well established by this method.