The balance of powers between the institutions has evolved
The European Council was established as a result of the summit meetings involving the Heads of State and Governments which have been taking place since 1969. These meetings used to take place at regular intervals; a resolution passed at the Paris Summit Conference in 1974 made them a permanent fixture in the shape of the European Council, yet they were embodied in the Treaty establishing the European Community. The Treaty of Lisbon continues the tradition of EU treaty revisions bringing changes to the institutional balance.
EU"S Balance of Power
The institutional balance of power was of a bi-polar nature as only the Council and the Commission were institutions vested with real powers. This changed with the granting of budgetary powers a European Parliament which had until then been limited to a purely consultative role through the amending treaties of 22 April 1970 and 22 July 1975. As a result a tri-polar Council Commission EP institutional balance emerged, with the third pole –the EP – acquiring increased legislative powers especially through the introduction in 1993 and the subsequent extensions of the co-decision procedure and increased powers over the appointment of the Commission with the successive reform rounds of the Single European Act (1987), the Treaty of Maastricht (1993), the Treaty of Amsterdam (1999) and the Treaty of Nice (2003).
The Treaty of Lisbon not only continues the strengthening of the Parliament’s position especially through a new massive extension of the fields to which legislative co-decision applies but it transforms the tri-polar into a four-polar system as it gives to the European Council for the first time the official status of an institution (Article 13(1) TEU) which is also vested with powers it had not been provided with explicitly before, such as, the power to “define strategic guidelines for legislative and operational planning within the area of freedom , security and justice" (Article 68 TFEU). Constitutionally, the summit meetings of the European Council will no longer be intergovernmental gatherings outside supranational European structures, as they had been for a period of time. The European Council will in effect be the Cabinet Government of the post-Lisbon union. Its individual members will be constitutionally obliged to represent the Union to their Member States as well as the Member States to the Union.
The Treaty of Lisbon has assigned to the High Representative of the Union for Foreign Affairs and Security Policy and Vice-President of the European Commission (HR/VP) a position somewhere in the middle between the institutional sub-triangle of Council, European and Commission, creating an extraordinarily hybrid position whose direct relationship to the EP as the fourth pole in the institutional balance is limited to consultation and information duties with no binding effects on action (Article 36 TEU). With this hybrid element and its four poles the post-Lisbon institutional balance bears thus little resemblance to the bi-polar system of the original European Communities, and the pre-Amsterdam triangle has become a quadrangle. 
At the moment none of the member states of the EU enforce all the decisions made by EU legislation. If the member state does decide to implement the decisions they may sometimes do it in a timely manner. This scenario implies that the European Union is somewhat of an intergovernmental organization. The European Union can only fully become a supranational organization if all of the member states let their guard down and agree to comply with all decisions and policies of the European Union. The ultimate concern of the Member States, in regard to becoming a total supranational body, is their loss of sovereignty and power.
The Commission, the European Parliament, and the European Court of Justice represent a more intergovernmental organization. While the Council of the European Union and the European Council represent a supranational organization. The Commission of the European Union has twenty members. Each one of the Member States is represented by at least one commissioner the largest five countries have two. The commissioners are elected nationally which would imply that the Commission is somewhat supranational. But in reality the commissioners are not there to represent national interest. “Upon taking office, each commissioner has to take an oath to the effect that he or she will serve the overall interest of the EU and will not take instructions from a national government or from any other body".  This oath should ensure that the Commission is and remains an intergovernmental organization but it does not.
The European Parliament has strengthened its position It has enhanced role in treaty revisions (48(2)-(6)TEU), use of ‘passerelles’ (48(7)TEU) and other flexibility provisions (e.g. criminal justice domain ), launching of enhanced cooperation (329(1)TFEU) and appointment of Commission (17(7)TEU) now fully co-equal budgetary powers. The Commission has weakened position. It has to face a constitutionally reinforced EP and European Council. The HR/VP partially undercuts institutional autonomy and homogeneity. The Council has an unchanged position other it is under a stronger European Council. The European Council has strengthened position as it has changed from a deliberative body into an institution capable of adopting legally binding decisions and also appoints and dismisses HR/VP.
The European Council has strengthened position making it more supranational through the definition of strategic guidelines for legislative and operational planning regarding AFSJ (68TFEU) and strategic interests added to the CFSP principles / guidelines function (26(1) TEU). The European Parliament has also strengthened its position.
The European Parliament has strengthened position through the extension of co-decision (ordinary legislative procedure) to 40 legal bases and full co-decision with Council under the budgetary procedure. The Commission has weakened position through the extension of co-decision means 40 more fields in which EP can seek direct legislative deals with Council, reducing significantly the Commission’s influence on legislative output. The Council has weakened position as it is forced to co-decide with EP in 40 additional fields and on the annual budget. European Council has strengthened position as it gains direct impact on legislative process under the referral clauses in the police and judicial cooperation domains.
The European Council and Commission have strengthened their position whilst the Council has weakened position. The European Council has unchanged position.
The European Parliament has unchanged position whilst the Commission has increased position in terms that the President’s power to appoint Vice-Presidents and to force a Member to resign without approval. The Council has weakened in terms that the rotating presidency loses direct link with the European Council presidency. The European Council has increased as there is enhanced continuity and leadership potential by new permanent President.
European Parliament has strengthened position as extended legislative co-decision and assent powers. Commission has weakened as the enhanced visibility of European Council President is likely to rival with that of Commission President. The Council and European Council have strengthened their position.
Since the inclusion of the European Council the European Parliament is the great winner, notwithstanding the new role of the national parliaments in the legislative process. The European Council has gained many new powers and is strengthened by its institutionalisation and its permanent President. As to the European Commission, its executive powers (including delegated legislation) have also been strengthened but its role in the political programming and in the legislative process may have been slightly undermined.  It is then probably the Council of ministers whose influence has been diminished, or the Member states who have shared more of their sovereignty.